US2256289A - Rail sanding apparatus - Google Patents

Description

P 1941- J. CANETTA RAIL SANDI'NG APPARATUS 8 Sheets-Sheet 1 Filed Dec. 50, 1939 Sept. 16, 1 941. J.-CANETTA 2,256,289

RAIL SANDING APPARATUS ATTORNEY J. CANETTA RA-IL SANDING APPARATUS Sept. 1 1941.

8 Sheets-Sheet 3 Filed Dec. 30, 1939 ATTORNEY Sept. 16, 1941. v J, CANETTA 2,256,289

RAIL SANDING APPARATUS Filed Dec. 50, 1939 s Sheets-Sheet 4 HUI 20 INVENTOR JOHN CANETTA BY Wa n ATTORNEY Sept. 16, 1941. CANETTA 2,256,289

RAIL SANDING APPARATUS Filed Dec. 30, 1939 8 Sheets-Sheet 5 mm 0 D mvzu'ro \JOHN GANETTA ATTORNEY Sept. 16, 1941. CANETTA 2,256,289 RAIL SANDING APPARATUS Filed Dec. 50 1959 8 Sheets-Sheet} 1H 'INVENTOR we I l -JOHN CANETTA I WQ ATTORNEY Sept. 16, 1941;

J. CANETTA RAIL SANDING APPARATUS Filed Dec. 30, 1939 8 Sheets-Sheet 7 R NW NEW INVENTOR JOHN CANETTA BY ATTORNEY Sept. 16, 1941. J. CANETTA RAIL SANDING APPARATUS Filed Dec. 50, 1939 a Sheets- Sheet a QEL INVENTOR dOHN CANET TA ATTORNEY Patented Sept. 16, 1941 UNETED STATES PATENT OFFICE RAIL SANDING APPARATUS Application December 30, 1939, Serial No. 311,721

52 Claims.

This invention relates to sanding apparatus and more particularly to the type for use on railway vehicles for sanding the track rails.

In order to decelerate or stop the modern ultra high-speed railway trains in the relatively short distances required to meet operating schedules and to insure the safety of the trains, it is necessary to employ braking forces which are greater than ever before used.

The maximum degree of braking force which however may be employed on any railway vehicle or train is limited by the coefficient of adhesion between the vehicle wheels and rails since a greater degree of braking force is liable to cause sliding of the wheels which results not only in producing flat spots on the wheels but also in an undesired lengthening of the distance required to bring the train to a stop. Th coefficient of adhesion of course usually depends upon the condition of the track rails, that is, whether the track rails are dry or Wet, and is much greater when the track rails are dry than when wet, and in fact is usually so low when the rails are wet as to prevent the use of braking forces such as required to provide a desired stop. To overcome this diificulty the use of sand on the track rails has been resorted to since it will provide a maximum and substantially uniform degree of adhesion regardless of the condition of the track rails.

Heretofore sanding of the rails has usually been effected automatically when an emergency application of the brakes on a train has been effected since the degree of braking provided on a train at this time is usually the maximum obtainable. Manually controlled sanding has also been provided on most of these trains and while it has been available for use at any time, as during service brake applications, the primary purpose thereof has been to provide sand on the rails for increasing the traction of the locomotive unit during acceleration, but it is believed that with the further development and us of ultra high speed trains, sanding of the track rails during service brake applications will become and be considered substantially as essential as during emergency brak applications, in order to provide under all conditions of operation the most uniform and efficient brak control of the train.

Sanding arrangements heretofore employed on railway vehicles have been designed to provide a substantially constant rate of flow of sand for sanding purposes. The same amount of sand has thus been provided for sanding the track rails interferes with the signal systems employed on railroads and is therefore undesirable.

One object of the invention is therefore to provide an improved sanding arrangement for railway vehicles which is operative to automatically a proportion the amount of sand supplied for sanding a track rail during sanding operation substantially in accordance with the actual requirements.

Still another object of the invention is to provide an improvedsanding arrangement such as above described which is operative in eiiecting both service and emergency brake applications and which may be entirely automatic in operation or which may be controlled manually by the operator.

A still further object of the invention is to provide an'improved sanding arrangement for a vehicle adapted at one time to provide sand for sanding at a rate which varies substantially in proportion to the speed of the vehicle and which may be operated at the will of the operator to provide a certain maximum rate of sanding.

Another object of the invention is to provide an improved sanding arrangement for a railway 5 vehicle adapted to supply sand for sanding a rail under said vehicle at a rate which varies substantially in proportion to the speed of the vehicle so as to avoid excessive use and waste thereof.

40 Another object of the invention is to provide an improved sanding arrangement for use on railway vehicles adapted to provide sand for sanding a track rail in an amount substantially proportional to thespeed at which the vehicle is operating whereby substantially the same amount of sand will be provided on a unit length of track rail for all train speeds so as to minimize waste and excessive use of sand.

Other objects and advantages will be apparent from the following more detailed description of the invention.

In the accompanying drawings; Fig. 1 is a diagrammatic view, partly in section and partly in outline, of a fluid pressure brake equipment for a railway vehicle and one form of the improved sanding arrangement associated therewith; Fig. 2 is a sectional View taken on the line 2-2 in Fig. 1; Figs. 3 to 5 are diagrammatic views mainly in outline of a portion of the apparatus shown in Fig. 1 and with which there is associated various modified forms of the invention; Fig. 6 is a diagrammatic View somewhat similar to Fig. 1 disclosing another embodiment of the invention; Figs. 7, 8 and 9 are diagrammatic views mainly in outline of arrangements disclosing different modifications of th structure shown in Fig. 6; Fig. 10 is a diagrammatic view mainly in outline of an apparatus embodying another modification of the invention; Fig. 11 is a diagrammatic development view of a part of a valve device shown in Fig. 10; and Figs. 12 and13 are diagrammatic views of a portion of the apparatus shown in Fig. 10 and disclosing modified forms thereof.

Description of embodiment of invention shown in Fig. 1

The fluid pressure brake equipment shown in Fig. 1 for the purpose of illustrating one application of the invention comprises an engineers automatic brake valve device I, a main reservoir 2, a feed valve device 3, an automatic brake controlling valve device such as a triple valve device 6, an auxiliary reservoir 5 and a brake cylinder device 6.

The engineers brake valve device I may be of the type disclosed in Patent No. 2,106,483 issued to Ellis E. Hewitt on January 25, 1938, and which is adapted to control the brakes on a vehicle or train through the medium of a brake pipe 'I.'

The brake valve device comprises a casing 8 to which the brake pipe 'I is connected and an operating handle 8a adapted to be turned in a horizontal plane for at one time reducing the pressure in the brake pipe I for effecting an application of the brakes on the vehicles of a train and for at another time effecting :an increase in pressure in the brake pipe for effecting a release of the brakes on the vehicles of the train.

The operating handle 8a is preferably of the safety control type which is also movable in a vertical plane, and is operative upon downward movement from the normal position shown, in all brake controlling positions of the handle, to actuate a sanding bail 9 which is mounted to pivot on a shaft I0 secured in. the brake valve casing. The sanding bail 9 is arranged to engage the stem II of a sand valve I2 upon downward movement of the bail for unseating said valve against a spring I3; such spring being provided for seating the valve I2 upon return of the handle 8a to its normal position.

The sand valve I2 is contained in a chamber I4 which is connected by way of a passage and pipe I5 to a fluid pressure supply pipe I6 which is supplied with fluid at a desired reduced pressure through the feed valve device 3 from the main reservoir 2. The Valve stem II is provided with a fluted portion extending from the valve through a chamber H. The chamber I1 is connected by a passage I8 to a sand pipe I9. The valve I2 is operative when unseated to supply the fluid under pressure from chamber I4 to chamber I7 and thence to the sand pipe I9, and when seated to cut off such supply of fluid under pressure.

The triple valve device 4 may be of any suitable type adapted to respond to either a service or an emergency reduction in pressure in brake pipe I, eifected by operation of the brake valve device I, to supply fluid under pressure from the auxiliary reservoir 5 through a pipe 69 to the brake cylinder device 6 to effect either a service or an emergency application of the brakes, respectively, on the vehicle. Upon an increase in pressure in brake pipe I the triple valve device l is adapted to operate to recharge the auxiliary reservoir 5 from brake pipe I and to connect the brake cylinder 6 to the atmosphere for effecting a release of the brakes on the vehicle. A further description of the construction and operation of the fluid pressure brake equipment on the vehicle is not deemed essential to a comprehensive understanding of the invention.

According to the embodiment of the invention shown in Fig. 1, an improved sanding apparatus is provided which is so associated with the fluid pressure brake equipment above described as to operate automatically when either a service or an emergency application of the brakes is effected on the vehicle to supply sand for sanding the track rails at a rate or to a degree which varies substantially according to the speed at which the vehicle is operating, so as'to thereby ensure most efl'icient braking of the vehicle but at the same time avoid excessive use and waste of sand. For the purpose of simplicity only the apparatus necessary to provide sand for one rail is shown in the drawings, it of course being understood that both rails of a railway track are to be sanded and that such duplication of devices or parts thereof as required to accomplish this end fall within the scope of the present invention.

The improved sanding apparatus shown in Fig. 1 comprises a sanding device 20, a cleaning device 2'I therefor, a pneumatic switch device 22, a pneumatic cylinder device 23, a timing valve device 24, and ceratin other parts which will be later brought out.

The sanding device 211 is of conventional structure comprising a casing 25 having therein a substantially horizontally extending sand carrying cavity 26. The cavity 26 is open at one end of the casing to an outlet pipe 21 for conveying sand supplied thereto from cavity 26 to a track rail 28 in front of a vehicle wheel 29. The opposite end of cavity 26 is open to an upwardly extending sand supply passage 30, the upper end of which connects to the bottom of a sand box 3| which is provided on the vehicle for carrying a supply of sand for sanding purposes and from which sand is adapted to flow by gravity through the passage 38 into the cavity 26.

An air jet 32 is disposed in cavity 26 below passage 36 and is so arranged as to direct a blast of air supplied thereto in the direction of the outlet pipe 21 for thereby blowing sand deposited by gravity in cavity 26 to said outlet pipe for sanding the track rail 28. The jet 32 is connected to a pipe 33 through which fluid under pressure is adapted to be supplied to the jet, and between said jet and pipe there is provided a check valve 34 for preventing sand from cavity 25 entering the pipe 33.

The cleaning valve device 2I is also of usual construction comprising a piston 35 having at one side a chamber 36 connected to pipe 33 and having at the opposite side a chamber 31 open to the atmosphere through a passage 38 and containing a spring 39 actingon said piston for urging same to the position shown. The piston 35 is provided with a stem 40 which extends through a suitable bore in the casing and which is provided on its end with a double beat valve "aasaz'ee 4| disposed to operate in a chamber 42. In the position which valve 41 is shown said valve is adapted to close communication between chamber 42 and a passage 43. The valve 41 is adapted to be moved by piston 35, when fluid under pressure is supplied to chamber 36, from the position shown to an opposite position into engagement with a seat 44 forclosing communication between the fluid pressure supply pipe I6 and chamber d2. During movement of the valve 41 between its two seated positions a limited flow of fluid under pressure is adapted to occur from the fluid pressure supply pipe It through the chamber 42 to passage 43 as will be apparent.

The passage 53 is connected by a pipe 45 to a passage 48 in casing 25 of the sanding device 20. One end of passage 46 is connected to a cleaning pipe 41 the outer end of which is preferably closed and which is provided with a plurality of spirally arranged outlet jets 48 through which a blast of air is adapted to be directed into passage 36 for loosening and blowing sand out of said passage to the cavity 26. t the end of passage 46 connected to pipe 45 there is provided a port 49 connecting said passage to cavity 26 and arranged to direct a blast of air from said passage toward the outlet pipe 2'! for blowing sand out of said pipe. By this arrangement, all of which is conventional, both the outlet pipe 21 and sand supply passage 30 are adapted to be cleaned upon initiating a sanding operation so as to insure prompt and intended flow of sand for sanding purposes, as will be later brought out.

According to the invention a slide valve is provided for controlling the flow capacity ofpassage 88 to supply sand by gravity from the sand box 3! to cavity 28. This slide valve normally closes communication through the passage 30 so as thereby to cut off all supply of sand to cavity 26 and is provided with a port 52 adapted 5 upon movement in the direction of the right hand, as viewed in Figs. 1 and 2 of the drawings, to open communication between the sand box 3| through passage (it to cavity 26. The

area of this communication and the capacity thereof to supply sand by gravity to cavity obviously depends upon the position of port 52 in valve 55 with respect to passage and increases upon move rent of the valve toward the The slide valve 5! is provided at one end with a stem 53 having a collar 54 adapted to engage the casing for defining the closed position of the valve, as shown in the drawings. A spring 55 is provided to act on collar 54 for moving the I valve 5! to its closed position. An electro-magnet SS is provided for controlling the position of the valve 5! and comprises an armature 57 operatively connected to the opposite end of the valve and an operating coil 58 connected across E2. The wirestli and G2 are connected, resp'ec tively, to fixed contact fingers Stand 64 which are arranged to be electrically connected by a movable contact 65 associated with the pneumatic switch device 22.

The pneumatic switch device 22 comprises a casing containing a piston E6 which is provided with a stem 61 carrying at its outer end the contact 65. At one side of piston 66 there is provided a chamber 68 which is connected by pipe 59 to the brake cylinder device 6. A spring it is provided to act on the opposite face of piston t for operating said piston to draw the contact 15 out of circuit closing relation with the contact fingers 63 and 64.

With the movable contact finger 65 in circuit closing relation with contact fingers 63 and 64 it will be noted that the output of generator BI is impressed on the operating coil 53 of the electrc-rnagnet 56 and will effect movement of armature 5"! and thereby of the slide valve 5| in the direction of the right hand, as viewed in Figs. 1 and 2 against the opposing and measuring pressure of spring 55. The extent of this movement of valve 5! is adapted to vary in accordancewith the output of the generator 5| as governed by the speed at which the vehicle is operating and, as will be apparent, the area of port 52 in valve 53, which controls the rate at which sand will be supplied from the sand box 3! to cavity 25 will therefore vary in accordance with the speed at which the vehicle is operating. These parts are so designed that when the vehicle is operating at a certain relatively high speed the slide valve 55 will be positioned with the full area of port 52 in said valve effective to supply sand to cavity 25. When the vehicle speed is substantially zero the slide valve will be positioned to substantially out 01f all supply of sand to cavity 26, and for all intermediate speeds the slide valve will be positioned so that the opening through port 52 for supplying sand to cavity 26 will vary the rate of sand supply to cavity 26 in proportion to the different speeds.

The pneumatic cylinder device 23 comprises a casing containing a piston 13 having at one side chamber 74 connected to pipe l9 and having at the opposite side a chamber 15 containing a spring 16 which acts on the piston for urging the same to the position shown in the drawings. The piston F3 is provided with a stem 11 extending through chamber l5 and an opening in'the end of the casing into coaxial alignment with the armature 51 of the electromagnet device 56. A release port 18 is provided through piston l3 connecting chamber 14 to chamber 15 and the latter chamber is open tothe atmosphere by way of a leakage groove 19 provided through the casing along stem TI. With the piston stem H! in its normal position shown and with the armature 51 of the electro-magnet device 56 also .is connected to the brake cylinder pipe '69 and having at the opposite side an operating stem 83 which projects into a chamber :84 connected to a pipe 85. A pair of oppositely seating valves 85 and El are provided in a chamber 88 in coaxial alignment with the piston stem 83. The

valve-86 is provided for controlling communication between chambers 88 and 84 and has a fluted stem 89 arranged to be engaged by the piston stem 83. .The valve 81 is arranged to control communication between chamber 88 and a chamber 90 and is provided with a fluted stem 9| extending into the latter chamber wherein a spring '92 is arranged to act on said stem for moving the valves 86 and 81 to their normal positions, shown in the drawings.

The chamber 90 in the timing valve device is connected through an air strainer device 9311 to the fluid pressure supply pipe l6. With the valves 86 and 81 positioned as shown in the drawings, fluid under pressure supplied from the supply pipe |6 to chamber 99 is adapted to flow past valve 81 to chamber 88 and then through a pipe 93 to a sanding reservoir 94 for charging said reservoir with fluid under pressure. The valves 86 and 81 are adapted to be shifted to their opposite positions by the piston 8| when fluid under pressure is supplied to chamber 82, and when thus positioned to close communication between chambers 90 and 88 and open communication between chambers 88 and 84 to supply fluid from the sanding reservoir 94 to the pipe 85.

The pipe 85 is connected to one end of a double check valve device 91 the other end of which is connected to pipe I9. The side outlet of the double check valve device 91 is connected to the pipe 33. The double check valve device comprises a double check valve 96 arranged to operate in the usual manner to control communication between the pipe 33 and the pipes I9 and 85.

Operation of embodiment of invention shown in Fig. 1

Whenever either a service or an emergency application of the brakes on the vehicle is effected by operation of the brake valve device I, fluid at the pressure supplied to the brake cylinder device 6 flows to piston chamber 68 in the pneumatic switch device 22 and to piston chamber 82 in the timing valve device 24.

The fluid pressure thus supplied to the switch device 22 actuates the piston 66 to effect movement of the movable contact 65 into engagement with the contact fingers 63 and 64 thereby connecting the coil 58 of the electro-magnet device 56 in circuit with the generator 6| operated from the wheel 29. The output of the generator is thus impressed upon the operating coil 58 of the electro-magnet device 56 and effects movement of the armature 51 and valve against the opposing force of spring 55 to a position dependent upon the speed at which the vehicle is operating at the time. This movement of the valve 5| opens communication betweenthe sand box 3| and cavity 26 in the sanding device through port 52 in the valve to permit sand to flow by gravity from said sand box to said cavity at a rate which is proportional to the speed of the vehicle.

At the same time as the pneumatic switch device 22 is thus operated fluid pressure supplied to piston chamber 82 in the timing valve device 24. actuates the piston 8| to unseat the valve 86 and to seat the valve '81. With the valve 86 unseated fluid under pressure flows from the sanding reservoir 94 to pipe 85 leading to one end of the double check valve 96. The fluid pressure in pipe 85 then shifts the double check valve 96 to the position for closing communication between pipe 33 and pipe I9 and for connecting the pipe 85 to the. pipe 33 whereupon fluid under pressure flows from pipe to pipe 33 and then to jet 32 in the sanding device and also to piston chamber 36 in the cleaning valve 2|.

The fluid pressure thus supplied to piston chamber 36 actuates piston 35 to effect movement of the double beat valve 4| from the position shown to its opposite position into engagement with the valve seat 44 and during such movement a limited flow of fluid under pressure occurs from the fluid pressure supply pipe l6 to the passage 43. The fluid pressure thus supplied to passage 43 flows to passage 46 in the sanding device 20 and then through jets 4B in the cleaning pipe 4'! to passage 30 for cleaning sand out of said passage and also from passage 46 through the port 49 to the sand pipe 21 for cleaning sand therefrom. This supply of fluid to jets 48 and to the port 49 is in the form of a sudden blast of short duration to accomplish the cleaning action just described.

At the same time as the cleaning device 2| is operated, as just described, fluid under pressure flows from pipe 33 past the check valve 34 and through the jet 32 into cavity 26 of the sanding device 20 and through said cavity to the outlet pipe 21, and this stream of air is adapted to pick up and carry the sand supplied to said cavity through the sand valve 5| to the outlet pipe 21 through which said sand is adapted to be conveyed to the rail 28 ahead of the wheel 29 for increasing the traction thereof.

The amount or quantity of sand thus supplied to the rail 28 is limited, as will be apparent, to the effective capacity of port 52 in valve 5| to supply sand from the sand box 3| to the cavity 26 and will be greatest when the speed of the vehicle and therefore the output of the generator 6| is sufficient to operate the electro-magnet device 56 to position the valve 5| so as to render the full area of port 52 effective.

As the speed of the vehicle is reduced during braking, the output of the generator 6| is adapted to reduce accordingly and the corresponding reduction in force of the electro-magnet device 56 permits the spring 55 to move the valve 5| toward the left hand to a position depending upon the reduction in vehicle speed, and as will be apparent, the effective opening through port 52 in valve 5| will be reduced in proportion so that the amount or quantity of sand supplied from the sand box 3| to cavity 26 will be correspondingly reduced. The supply of sand for sanding the track rail 28 will be thus varied in proportion to the speed of the vehicle wheel 29 and the parts are so designed and arranged that the amount or quantity of sand supplied for sanding rail 28 will provide a substantially uniform degree of sanding regardless of the speed at which the vehicle is operating. Efficient braking of the vehicle is thereby ensured, and at the same time excessive use or waste of sand avoided.

The volume of the timing reservoir 94 is such as to provide for the flow of fluid under pressure through the jet 32 for a sufficient length of time to supply sand through the supply pipe 21 to the rail 28 until the vehicle is brought to substantially a complete stop from the maximum speed at which the vehicle might be operating at the time an application of brakes is initiated. The valve 5| and its control by the generator 6| are so arranged that at the time the vehicle speed reduces to substantially zero the spring 55 will have fully closed the valve 54 against the opposing reduced force of the electro-magnet 56. By this arrangement sand will not be supplied to the rail 28 and thus wasted when the vehicle is stopped and there is no use for sand.

When the fluid pressure is substantially completely vented from the sanding reservoir 94 and piston chamber 36 of the cleaning valve device spring 39 acting on piston 35 returns the piston 35 to its normal position shown thereby moving the valve 4! out of engagement with seat id and back to its normal position shown. During this movement of the double beat valve 4! a sudden but limited blast of fluid under pressure will fiow from the fluid pressure supply pipe it to passage 43 and then to the sanding device 29 for efiecting cleaning thereof in the same manner as occurred at the time the sanding operation was initiated. The sanding device 2E3 is thereby conditioned to properly function upon a subsequent application of the brakes.

As is well known, it is customary to reduce the degree of brake application on a vehicle or train as the speed reduces in order to avoid too rapid deceleration thereof or the possibility of sliding of wheels. As a result, at the time the vehicle comes to a substantial stop the degree of pressure still acting in the brake cylinder device 6 will be relatively low. The spring El in the pneumatic switch device 22 is so designed as to move the piston 56 back to its initial position for thereby disengaging the contact 55 from the contact fingers 53 and 6 whenever the pressure in the brake cylinder becomes reduced to the relatively low degree that might exist at the time the train is brought to a full stop. By this arrangement the coil 58 of the electro-magnet device 55 is disconnected from the generator 5! at a time when no further sanding of the rail 28 is required so as to thereby avoid overheating of said coil.

If when the brakes on the vehicle are applied the vehicle wheel 29 should cease to turn on the rail 28 the output of the generator 6! and the force of the electro-magnet device 56 will immediately reduce to substantially zero and as a consequence permit spring 55 to promptly close the valve 5! and thereby cut off the supply of sand to the rail 28 in front of the wheel 29. This is very desirable in that it will avoid excessive abrasion of the wheel and rail during the period of wheel sliding. If, subsequently, during the brake application the wheel 29 starts turning on the rail 23 then current is again delivered by the 5 generator 51 and operates the electro-magnet device 56 to again sand the rail 28 for increasing the traction between said wheel and rail.

When the operator operates the brake valve device l to effect a release of the brakes on the vehicle subsequent to an application, fluid under pressure is vented from piston chamber 82 of the timing valvedevice 24 along with that from the brake cylinder device 6 and when reduced sufliciently the spring 92 acting on the valve stem 9| unseats the valve 87 and seats the valve 85. With the valve 8? thus open the sand reservoir 84 is again charged with fluid under pressure from the fluid pressure supply pipe it so as to be in condition for a subsequent sanding operation, such as just described.

It, at any time, the operator desires to supply sand to the rail 28, for increasing the degree of adhesion between the rail and wheel 29 either during braking or during acceleration of the vehicle, he may depress the brake valve handle 8a. and thereby operate the bail 51 to move the valve stem H in a downwardly direction for unseating the sand valve l2. V fhen the sand valve [2 is thus unseated, luid from the supply pipe i5 flows to chamber l1 and then through passage I8 to pipe l9.

Fluid under pressure thus supplied to the pipe i9 flows to piston chamber H3 in the pneumatic cylinder device 23 and therein acts on piston 13 for effecting movement thereof in the direction of .the right hand against the opposing pressure of spring 15. ton stem l'i engages the armature 51 of the electro-magnet device 56 so that further movement of the piston 13 then acts through said armature to shift the slide valve 5| against the pressure of spring to the position in which the full effective area of port 52 is available to provide for a maximum flow of sand from the sand box 3! to cavity 26 in the sanding device 20.

At the same time as the pneumatic cylinder device 23 is thus operated, fluid under pressure supplied to pipe It! also flows to the double check valve device 51' and operates the check valve 96 to disconnect pipe from pipe 33 and to connect pipe 33 to pipe I!) so that fluid pressure then flows from the pipe I!) to pipe 33 and then to the jet 32 in the sanding device and to the cleaning device 2!. The cleaning device then operates in the same manner as hereinbefore described while the fluid pressure supplied to the jet 32 blows the sand supplied through the valve 55 to cavity 26 out of said cavity to sand pipe 2'! and then to the rail 28.

The piston '13 may be operated to actuate the valve 5! as just described when the electro-magnet 55 is effective during braking or at any other time desired. This is however immaterial since whenever the piston 13 is operated it provides sufficient force to overcome the spring 55 and move the valve 5| to its full open position.

Whenever it is desired to terminate manual sanding of the track'rail 28, as just described, the operator permits the handle 8a of the brake valve device I to return to its normal position shown thereby relieving the unseating pressure on valve !2 which permits spring It to seat said valve and cut off the supply of fluid under pressure to pipe Iii. The fluid pressure acting in piston chamber i i of the pneumatic cylinder device 23 is then dissipated through the release port it to chamber '15 and then to the atmosphere through the leakage groove 19 whereupon spring 16 returns the piston 13 to its normal position shown. Spring 55 acting on the slide valve 5| then returns said supply valve to its normal position so as to cut oil further flow of sand to the will then operate as heretofore described to effect cleaning of the sanding device 20.

Since automatic sanding of the track rail 23 is insured whenever an application of the brakes on the vehicle is effected, regardless of whether such application is a service or an emergency application, the operation of the brake valve handle 8a to manually effect sanding of the rail during braking will seldom if ever be resorted to as will be apparent.

rails during acceleration and at any other time in case of emergency.

After slight movement, the pis- However, this manual sanding control provides for the usual sanding of the It is customary to make a standing test of the brakes on a train before the train leaves a terminal, that is, a test with the train not under motion, under which condition there is obviously no need for sand on the rails. As will be apparent, no sanding of the rails will be effected with the present embodiment of the invention under the condition just described, since the sanding is dependent upon movement of the vehicle.

Description of embodiment of invention shown in Fig. 3

In this embodiment of the invention means are provided for adjusting the position of the sanding valve 5! in the sanding device 20 by fluid at a pressure which is varied according to the speed at which the vehicle is operating, instead of by the generator 6| and electro-magnet device 56 shown in Fig. l and hereinbefore described. 7 As shown in Fig. 3, a pneumatic cylinder device IOI is employed to cooperate with spring 55 under all conditions of sanding to position the sanding valve 5!. The cylinder device I! may be the same as the cylinder device 23 shown in Fig. 1 except in the device IOI there is no spring provided at the low pressure side of the piston I3 to oppose movement thereof upon the supply of fluid under pressure to chamber I4 at the opposite side of the piston. Extending from the slide valve for engagement by the pistonrod I1 is any suitable member such as armature 51 hereinbefore described.

The apparatus shown in Fig. 3 further differs 'from tha shown in Fig. 1 in that it embodies a speed controlled device I02 for supplying fluid at a pressure which varies in accordance with the speed at which the vehicle is operating, and a cut-ofi valve device I03 for controlling the supply of fluid from the device I02 to the pneumatic cylinder device IOI.

The device I02 comprises a casing having a stationary portion I04 embodying a self-lapping valve mechanism including a supply valve I05 and a release valve I06, and a rotary portion I01 embodying a centrifuge device including weighted levers I08 pivoted intermediate their ends to said rotary portion III! of the casing and rotatable therewith. The rotary casing section I01 is adapted to be rotated according to the speed of the vehicle as by an endless belt drive from an axle or other element driven according to the speed of the vehicle to a pulley I09 coaxially secured to the casing I01. A rod or stem IIO extends into the stationary and rotary portions of the casing and is slidable with respect thereto and the end of said rod in said rotary portion is engaged by the inner ends of levers I08. As the speed of the vehicle increases the outer weighted ends of the levers I08 are adapted to move outwardly for urging the rod H0 in the direction of the stationary portion I04 of the casing, while upon a decrease in vehicle speed the weighted ends of the levers are adapted to move inwardly to permit movement of rod H0 in the opposite direction.

A movable abutment in the form of a piston I I I is slidably mounted in the stationary casing section' I04 and is secured to the lower end of the stem I I0. At the upper side of the piston I I I is a chamber II2 which is constantly open to the atmosphere through a port H13. At the opposite side of piston III is a chamber II4 which contains the release valve I06 and a light bias spring II5 which acts on the piston for urging same in the direction away from the release valve. The piston III is provided centrally with an exhaust passage II6 which is at all times open to chamber H2, and the valve I06 is arranged to control communication between the chamber H4 and said passage.

The supply valve I05 is contained in a chamber II! and said valve and the release valve I06 are connected together by a stem IIB which extends loosely through a passage H9 connecting chambers III and II4. A spring I20 in chamber II'I acts on the supply valve I05 for urging it to its closed position shown in the drawings. The chamber III is connected to a pipe I2I through which fluid at the pressure carried in the supply pipe I6 is adapted at all times to be supplied to said chamber.

Briefly, the operation of the speed controlled valve device I02 is as follows: Assuming that the vehicle is moving along the track the rotary housing I0! is caused to turn at a speed which is proportional to the rate of movement of the vehicle. The action of centrifugal force on the weighted levers I08 causes said levers to move outwardly and exert a force on stem I I0 for moving the piston I I I in a downwardly direction into engagement with release valve I06 so as to close communication between the chamber I I4 and release passage II6. As the action of centrifugal force on the weighted levers I08 continues to force the piston III down, said piston acts through the release valve I06 and stem IIB to unseat the supply valve I05 whereupon fluid under pressure flows from chamber I" through the passage II9 to chamber H4 and therein acts on the piston III in opposition to the action of centrifugal force on said piston.

When the pressure of fluid in chamber H4 is thus increased sufficiently, acting in conjunction with the relatively light biasing pressure of spring II5, to overcome the action of centrifugal force on piston II I, said piston is moved upwardly to permit the supply valve I05 to close to prevent further increase in pressure therein. Thus if the vehicle is operating at a relatively high speed a relatively high fluid pressure will be obtained in chamber II4, while in case the vehicle is operating at a relatively low speed the pressure of fluid obtained in said chamber will be at a correspondingly low degree. If the speed of the vehicle increases an increase in centrifugal force will actuate the piston III to provide a proportionate increase in the pressure of fluid in chamber II4, as will be evident. In case the speed of the vehicle reduces, the action of centrifugal force on piston III reduces a corresponding amount, which permits pressure of fluid in chamber I I 4 to move said piston in an upwardly direction and out of contact with the release valve I06. As a result, fluid under pressure is released from chamber II4 through the exhaust passage I I6. This release of fluid from chamber II4 reduces the pressure of fluid on piston II I and, as will be readily apparent, when this pressure is reduced sufliciently the action of centrifugal force transmitted through stem IIO to said piston will move the piston back into engagement with the release valve I06 for preventing the further release of fluid under pressure from chamber I I4. In this manner the pressure in chamber II4 will be maintained proportional to the speed at which the vehicle is operating at all times.

The cut-off valve device I03 comprises a casing having a chamber I23 which is at all times connected to chamber H4 in the speed controlled device I02 by way of a pipe I24. Whenever the vehicle is operating it will therefore be apparent that chamber I23 will be charged with fluid at a pressure proportional to the speed of the vehicle.

The casing of the cut-01f valve device also has a chamber I25 open to chamber I23 through a bore I26 and also open to an outlet pipe I21. A valve I28 is provided in chamber I23 for controlling communication between chamber I25 and the bore I26. A spring I29 in chamber I23 acts on valve i28 for normally urging it to its seat.

The valve 528 is connected to a stem I33 which projects from one face of a piston I-3I through chamber I25. At the opposite side of piston I3i there is provided a chamber I32 which is connected to a pipe I33 leading to the brake cylinder pipe 59. A gasket I 34 is provided on the side of piston I3I adjacent chamber I25 for engagement by said piston.

The outlet pipe i21 is connected through a check valve device I38 to a pipe I35'which leads to piston chamber 14 in the pneumatic cylinder device II. The pipe I9 through which sanding on the vehicle is adapted to be manually controlled in the same manner as described in connection with the construction shown in Fig. l is also connected to the pipe I35 through a check valve device I31.

Operation of embodiment of invention shown in Fig. 3

Whenever fluid under pressure is supplied to the brake cylinder device for applying the brakes on the vehicle, fluid also flows from the brake cylinder pipe 69 through pipe I33 to piston chamber 832 in the cut-off valve device I03 and therein acts on the piston I3I to effect movement thereof into sealing engagement with the gasket I33. This operation of the piston I3I acts to unseat the valve I26 and thereby permit fluid at the pressure supplied by the speed governor device I02 to chamber I23 to flow to chamber I25 and then through pipe I21, check valve device I38 and pipe I35 to piston chamber 14 in the pneumatic cylinder device IBI.

The pressure of fluid thus obtained in chamber 14 acts on piston 13 to effect movement thereof in the direction of the right hand against the opposing pressure of spring 55. The extent which the piston 13 is thus moved depends upon the pressure of fluid supplied to chamber 1 3, said fluid pressure and that of spring 55 cooperating to define a position of the sanding valve 5 I shown in Fig. 1, which corresponds to the pressure of fluid acting on the piston 13 and therefore to the speed at which the vehicle is operating. Sand is thus supplied from the sand box 3! to the sanding device 29 at a rate determined by the speed of the vehicle.

As the vehicle speed reduces the speed controlled device !82 acts to reduce the pressure of fluid in chamber H4 as above described and as a result the pressure of fluid in chamber 14 acting on piston 13 in the pneumatic cylinder device It! correspondingly reduces through a small leak port I35 which may be provided in pipe I35, it being noted that with this construction the speed controlled device acts to maintain the pressure of fluid in chamber M substantially equal to that in chamber IM against the continuous loss through this small leak port. As a result of the reduction to fluid pressure in chamber 1 3 spring 55 acts to urge the sand valve 5| in the direction of the left hand to a position where the spring force is counterbalanced by the reduced pressure of fluid in chamber 14. The valve 5! thus assumes a new position corresponding to the reduced speed at which the vehicle is operating and reduces the amount or quantity of sand supplied to the sanding device 20 in proportion to the reduction in speed. The spring 55 will thus continue to act as the pressure of fluid in chamber 14 continues to be reduced by the speed controlled device I02 as the vehicle speed reduces to cause further corresponding changes in the position of the sand valve 5| to thus reduce the rate at which sand is supplied from the sand box 3| to the sanding device 26 in proportion to the reduction in speed of the vehicle. In other words, by varying the pressure of fluid supplied to chamber 14 for acting on piston 13 according to the changes in speed at which the vehicle operates the position of valve 5i will be varied by spring 55 to vary the rate at which sand is sup plied to the sanding device 2!] for sanding the track rail in proportion to the vehicle speed, in the same manner as accomplished electrically with the apparatus shown in Fig. 1.

If, when the brakes on the vehicle are applied the wheel driving the speed controlled device I02 should cease rotation and start sliding on the rail, the action of centrifugal force on the weighted levers I58 will promptly reduce to zero, as a result of which, the piston III will be moved to the position shown by the pressure of fluid and that of spring I I5 in chamber I I4. The supply of fluid to the cylinder device Iii! will be thus cut off and the fluid pressure in chamber 14 thereof will then promptly vent to the atmosphere through the leak port I 36. As a result, spring 55 will operate the Valve 5| to cut off the supply of sand for sanding the track rail. If subsequently the wheel for driving the speed. controlled device I32 should again start rotating, then fluid under pressure will again be supplied to the cylinder device IfiI to efiect the supply of sand for sanding the rail at a rate proportional to the rate of such rotation, as will be apparent. It will be noted that during sanding operation, the leak port I35 in pipe I35 provides a constant leak of fluid under pressure from chamber I I4 in the speed controlled device I52 and another purpose for this is that it causes the piston III to be constantly in operation during the sanding period so as to thereby remain in a very sensitive condition to accurately vary the pressure of fluid in chamber 1% of the cylinder device Ilil according to changes in vehicle speed. The check valve I31 is provided to prevent the flow of fluid under pressure from pipe I35 as to pipe I9 leading to the brake valve device I during automatic sanding operation just described.

Sand will continue to be supplied for sanding the track rail as above described as long as fluid is supplied to piston chamber 14 in the pneumatic cylinder device at a pressure suflicient to open the valve 5I to any degree. The supply of sand may be terminated either by a reduction in brake cylinder pressure in piston chamber I32 to a relatively low degree, such as five pounds, which may occur at substantially the time the vehicle comes to a stop and at which pressure the valve I28 may be closed by spring I29, or said supply of sand may be terminated by the speed controlled device IIl2 at substantially the time the vehicle comes to a stop when the force of the light bias spring II5 becomes sufficient to overbalance the action of centrifugal force on the ment connected to one contact finger I42.

weighted lever'arms I08 and move piston III away from the release valve I03. In either case the supply of sand to the rails will be terminated by the time the vehicle stops and waste of sand will be avoided. The primary purpose of the cut-oil valve device I03 however is to prevent the supply of fluid under pressure to the pneumatic cylinder device IOI when the brakes on the vehicle are released,

Since the speed controlled device I02 acts to supply fluid under pressure for effecting sanding only when the vehicle is under motion it will be noted that sand will not be supplied for sanding a track rail when making a standing test of the brake system.

In case it is desired to manually effect sanding ofthe track rail the brake valve device is operated to supply fluid under pressure to pipe I9 through which it flows to the double check valve device 91 and thence to'the sanding device for effecting operation thereof in the manner before described. Fluid pressure supplied to pipe I9 also flows through the check valve device I31 to pipe I35 and thence to piston chamber 14 in the pneumatic cylinder device WI. The pressure of fluid thus provided in chamber 14 acts on the piston I3 to efiect movement of the sand valve 5| to its wide open position against the opposing pressure of spring 55. The maximum amount of sand for sanding of the track rails is thus obtainable upon operation of the brake valve device, as will be apparent. The check valve I38 acts during manual sanding, just described, to prevent the flow of fluid under pressure from pipe I35 to pipe I21.

Description of embodiment of invention shown in Fig. 4

In the arrangements shown in Figs. 1 and 3 of the drawings sanding of the track rail during braking is eifected automatically whenever either a service or an emergency application of the brakes is effected on the vehicle. In Fig. 4 of the drawings is shown an arrangement whereby all sanding, including sanding according to speed, r

is directly under the control of the operator of the vehicle.

In the apparatus shown in Fig. 4, the sanding bail 9 is provided with an extension I40 on the lower face of which is fixed an electrical contact I adapted upon downward movement of the bail to engage two flexible contact fingers I42 prior to engagement of the bail with the sand valve stem II.

The wire 60, shown in Fig. 1 connected to the pneumatic switch device 22, is in this embodi- In this embodiment the electromagnet device 56 is employed to position the sand valve 5I and one terminal of the coil 58 of said device is connected to wire 59 as in Fig. 1 while the other terminal of said coil is connected to a wire I43 leading to the other contact finger I42. It will thus be evident that the contact I40 associated with the sand bail 9 and the contact fingers I42 constitutes a manually operative switch for controlling the energization and deenergization of the electro-magnet device 56.

A supply magnet valve device I44 is provided for controlling the supply of fluid under pressure to the sanding device 20 and to the cleaning device 2| in place of the timing valve device 24 shown in Fig. 1. This magnet valve device I44 comprises a magnet I45 connected across the wires I43 and 59 in parallel with the electromagnet device 56 and a valve I46 arranged to be opened upon energization of the magnet I45. The valve I45 is contained in a chamber I41 which is connected to the fluid pressure supply pipe I5 and in said chamber there is provided a spring I48 acting on the valve for seating same upon deenergization of the magnet I45. The valve I46 is provided for controlling communica: tion between chamber I41 and a chamber I49 which is connected to a pipe I50 leading to the double check valve device 91 in place of the pipe shown in Fig. 1.

Operation of embodiment of invention shown in Fig. 4

Whenever it is desired to effect sanding of the track rail 28 at a rate proportional to speed during braking, the operator depresses the brake valve handle 8a. to a degree suflicient for operating the sanding bail 9 to move the contact I40 into circuit closing relation with the contact fingers I42 for thereby connecting the electromagnet device 56 and also the magnet valve device I 44 in circuit with the generator 6| which is secured to rotate with the wheel of a vehicle as shown in Fig. 1 and as hereinbefore described. As a result the electro-magnet device 56 is energized and operates in the same manner as hereinbefore described to position the sanding valve 5I against the pressure of spring 55 so as to thereby supply sand from the sand box 3| to chamber 26 in the sanding device 20 at a rate depending upon the speed at which the vehicle is operating.

At the same time as sand is thus supplied to the sanding device 20 the eenrgization of the magnet I44 unsea-ts valve I48 and supplied fluid under pressure from pipe I6 to pipe I50 and then through the double check valve device 91 to the sanding device 20 for blowing the sand to pipe 21 for flow to the track rail.

The amount or quantity of sand supplied for sanding the rail will with this embodiment of the invention vary in proportion to the speed of the vehicle as will be apparent and will continue so long as the operator maintains the brake valve handle 8a in a position in which the contact I40 bridges the contact fingers I42 or until the vehicle is brought to a substantial stop at which time the pneumatic switch device 22, shown in Fig. 1, will operate to open the circuit through the electro-magnet device 56 and the magnet valve device I44 to cut oif the supply of sand.

In this embodiment of the invention the maximum amount of sand for sanding of the track rails may be obtained at any time by further depression of the brake valve handle 8a and consequent operation of the bail 9 to unseat the sand valve I2 for supplying fluid under pressure to pipe I 9, as will be apparent.

Description of embodiment of invention shown in Fig. 5

In this embodiment of the invention all sanding of the track rails is adapted to be controlled manually as in the embodiment just described but diiTers therefrom in that arrangements are provided for positioning the sand supply valve 5I pneumatically in a manner'similar to that disclosed in Fig. 3 and above described.

As in Fig. 3, the speed controlled device I02 and cut-off valve device I03 are provided to control the supply of fluid at a pressure dependent upon the speed at which the vehicle is operating for controlling the operation of the pneumatic cylinto the pneumatic cylinder device IOI from the speed controlled device I02 is however under the manual control of the operators brake valve handle 8a as will now be described.

In the brake valve device there are provided two poppet valves I 39 and II which are arranged side by side and adapted to be simultaneously operated by a sanding bail I 52 upon depression of the brake valve handle 8a. The valve I39 is contained in a chamber I54 which is connected through a passage I55 to the fluid pressure supply pipe I6 and is adapted to control communication between said chamber and a chamber I56 which is connected through a passage I51 and a pipe I58 leading to the jet 32 in the sanding device 20 and to the cleaning device 2|. The valve I39 is provided with a stem I59 extending through chamber I56 and through the casing of the brake valve device into operating alignment with the sanding bail I52.

The valve I5I is contained in a chamber I60 which is connected by way of passage and pipe I6I to check valve device I30 and thence through pipe I21 to the cut-ofi valve device I03 and is provided for controlling communication between said chamber and a chamber I62 which is connected through a passage and a pipe I63 to the pneumatic cylinder device IOI. The valve I5I is provided with a stem I64 which extends through chamber I62 and the casing of the brake valve device into operating alignment with the sanding bail I52, said stem and the stem I59 being arranged to be engaged by the sanding bail I52 at substantially the same time upon downward movement thereof.

A spring I66 in chamber I54 acts on valve I39 for urging it to its seated position shown, while a spring I61 in chamber I60 acts on the valve I5I for urging it to its closed position also shown.

Disposed in a chamber I68 is a sand valve I69 adapted to perform the function of the sand valve I2 shown in Fig. 1. below and in coaxial relation with the valve I39 and is provided with a stem I which extends through a port connecting chambers I54 and I68. This stem is of such length that with both of the valves I39 and I69 seated there is slight clearance space between said stem and the valve I39 to provide for unseating of the valve I39 before engagement of valve I39 and said stem. Chamber I69 is connected through a passage III to the passage and pipe I63.

Operation of embodiment of invention shown in Fig. 5

Whenever the brakes on the vehicle are applied and it is desired to efiect sanding of the track rail at a rate depending upon the speed at which the vehicle is operating the operator depresses the handle 8a sufficiently to actuate the sanding bail 52 to unseat the valves I39 and I 5I without however unseating the valve I69. The unseating of valve I5I permits fluid at a pressure supplied by the speed controlled device I02 through the cut-off device I03 to chamber I60 to flow to chamber I62 and then through passage and pipe I63 to the pneumatic cylinder device IIII which is thereby operated to position the valve 5I to supply sand from the sand box 3I to the sanding device at a rate or in a quantity which is proportional to the speed at which the vehicle is operating.

At the same time as sand is'thus supplied to Th valve I69 is arranged the sanding device 20 fluid under pressure from the supply pipe I6 flows past the valve I39 to chamber I56 and then through passage I51 and pipe I58 to the sanding device 20 and cleaning device 2| for operating same in the same manner as hereinbefore described to blow the sand sup-1 plied to said sanding device through pipe 21 to the track rail for sanding same.

The speed controlled valve device I92 operates as hereinbefore described to reduce the pressure supplied for actuating the pneumatic cylinder de vice IOI as the speed of the vehicle reduces, and

- accordingly, the sand valve 5| is operated by the spring 55 to reduce the rate at which sand is supplied to the sand device 20 in proportion to the reduction in vehicle speed. The amount of sand supplied to the track rail 28 for sanding same will thus be varied such as to provide for a uniform degree of sanding regardless of the vehicle speed.

The operator may terminate sanding at will by removing pressure from handle 8a to permit closing of valves I39 and I5I in which case the leak port I36 provided, in this embodiment, in pipe I63 will promptly dissipate the fluid pressure from the pneumatic cylinder device I9I and permit closure of valve 5I.

In case the operator maintains the valves I 39 and I5I open throughout the stop, the supply of sand will be terminated automatically either by closure of the cut-oi? valve device I63 when the brake cylinder pressure is reduced to a relatively low degree or upon failure of the speed controlled device I02 to further supply fluid under pressure which will occur at the time the vehicle comes to a substantial stop.

Whenever the operator desires to supply the maximum amount of sandto the track rail either during braking or acceleration he depresses the handle 8a to a maximum degree and in so doing moves the valve I39 into engagement with the valve stem I59 and unseats the valve I69. Fluid from the supply pipe I6 supplied to chamber I56 then flows past the valve I69 to chamber I68 and then through passage III, and. pipe I63 to the pneumatic cylinder device .IOI wherein this pressure acts to fully open the sand valve 5| against the opposing pressure of spring 55. The maximum amount of sand is thus supplied to the sanding device 29 for sanding purposes, and fluid under pressure continues to be supplied in this position of the brake valve handle past the valve I39 and through pipe I53 to the sanding device 26 for blowing the sand supplied thereto'to the track rail. In order to terminate this sanding of the track rail the operator relieves manual pressure on the brake valve handle 8a which permits the various springs to seat the valves I69, I5I, and I69 as will be apparent.

By this arrangement the communication 30 connecting the sand box 3I to cavity 26 in the sanding device 20 may always be fully open to permit a maximum rate of flow of sand to said cavity but theamount of sand which will be blown from said cavity-to the-outlet pipe .-21 for sanding the track rail will vary according to the amount or pressure of fluid supplied through the jet 32.

When the brakes on a vehicle are applied the degree of application depends upon the pressure supplied to the brake cylinder-device. It is customary to provide amaximum degree of pressure in the brake cylinder at the time an application of the brakes is initiated and to gradually reduce this pressure as the speed of the vehicle reduces, either by automatic means which may be controlled by the speed of the vehicle, or manually by the operation of a brake valve device. In either'casethe brake cylinder pressure is generally reduced according to the reduction in-vehicle speed and therefore is'usually' at all times during .brakingsubstantially a function of speed.

In the embodiment of the invention shown in Fig. 6 advantage is taken of this relation'between'brake cylinder pressure and vehicle speed to vary the amount or pressure of fluid supplied to the jet 32 in the sanding device 29'for blowing sand to the track rail whereby the amount of sand supplied for sanding purposes will vary substantially as the vehicle speed varies.

The brake equipment shown in Fig. 6 is, for the purpose of simplicity, adapted to be manua1ly.controlled,and let it be assumed-thatthe triple valve device 4 is of the type adapted; to efiect a graduated release of fluid from brake cylinder 6 upon the usual graduated release operation of the brake valve device I by the operator whereby the pressure .of fluid in the brake cylinder device during deceleration of. the vehicle may be maintained substantially .proportional to the speed at which the vehicle is running.

According to this embodiment of the invention the pressure existing in the brake cylinder device 6, when the brakes on the vehicle are applied, is employed as apilot pressure for controlling a differential relay valve device I which is adapted to operate to provide a corresponding pressure in a pipe I19 leading to the jet 32 in the sanding device 28 and to the. cleaning device 2I. A timing valve device I'I4is provided for control by the pressure of fluidinthe sanding reservoir 94 to limit the length of time which the relay valve device I15 :will operate to supply fluid under pressure for sanding purposes. The valve device 24 is provided for con trolling the operation of the timing valve device I14 according to the pressure existing .in the brake cylinder 6.

'The'relay valve device I151 comprises. a movable abutment in the form of a flexible diaphragm I11 having at one side a chamber I18connected to a pipe I19 and having at the opposite sidea chamber I81] connected through a chamber'IBI to the pipe I16 leading'to the sanding device 20 and cleaning device '2I. A sliding stem l82 is provided for movement by the. diaphragm I11 upon deflection thereof in a downwardly direction while a spring 'lfidactson the stem for .moving it in the opposite direction. A/rocking beam I84 in chamber ISI i pivotally connected intermediate its ends to the stem I82.

The release valve I is connected to the beam Oneend of the beam I84 is arranged to control'the :op-

I84 for movementtherewith and isprovided for controlling communication -.betw.een chamber I8I and a release port-I81 which leads to the atmosphere. The supply valveIBS-is contained in a chamberI88 :which is connected by a; pipe I89 to the fluid pressure supply pipe I6. A spring I90 in chamber I88 is .providedfor urging the supply I86 to. its-closed position.

The pipe I19 connects chamber 1 I18 totthe side outlet of. double check valve device. 91. One end of the double check valve.-91 is connected to-pipe I9 .asinFig. 1 throughwhich fiuid-under-pressureisadapted to be supplied for sanding of the track. railat any time. Thelother endrof .the double check valve .deviceisconnected to.the pipe 'I9I which leads to achamber I92 in the timing valve device. I14.

The timing valve device I14 comprises-a casing containing apiston I93havingatone side a chamber I94 which is connected to the timing reservoir pipel93. Inthe casingthere areprovided twooppositelyseating valves I95..and I96 having fluted stems which engage in chamber I92. The valve I95 is contained ina chamber I91 which is open-to the atmosphere through a vent port I98. The piston I93 has astem I99 extending into chamber I91 forcontrollingthe valveI-95 and-the oppositely seating valve -L96. The valve I96 is contained in a .chamberJIll) which is connected to the brake cylinder pipe 69. A spring 2M acts on;the valve I96.for.urging it toits seated position andforurgingthe valve I95 out of engagement with its seat.

Operation of embodiment. ofinventz'on shown in Fig. '6

'When-the brakes on the vehicle are released and thebrake cylinder 6 is thereby void of'fluid under pressure, piston chambertllz'in' the valve device 24 is likewise vented'which permits spring 92110 unseat'the valve 81-an'd"to seat the valve 86. This 'permits fluid under pressure .to 'flow from'th'e flu-id pressure -supply'pipe I6 through chamber '90, past the valve -81 to "chamber 188 and then through-piped?" leading to the timing reservoir =94 -and' to piston chamber'I94 inthe timing valve device I14. As a-result, the timing reservoir-94 is charged with'fluid atthe'pressure --supp1ied to the supply pipe I6-and this pressure-acting in chamber I94-of thetiming valvedevice on 1 piston I 93 shifts said piston to =a-nd 'holds same in theposition shown in which supplied to the brake cylinder device then 'flows through-pipe- 69 to chamber 82 in the-valve'device; 24. and alsoto chamber 209 in the timing -va-lve:device I19. Fluid" at brake cylinder pressure-thussuppliedto chamber 290 flows past the unseated valve I99 to .chamber I92 and then through ,thedouble. check valve :device 91 to. diaphragm. chamber I 18 in the relay valve "device I I15. The pressure of fluid .thussupplied to :cham- ;ber I 18in the relay valve-:devi'cexl 1.5 lactsio-n the diaphragm 1 I11 and .zdeflectssame. in .a down- :wardly-rdirection :wh-ich moves the stem 1'82 .and

thereby the fulcrum for beam I84 in the same direction.

Durin the initial downward movement of stem I82, as just described, one end of the beam I84 fulcrums about a stop screw 283 provided in the casing, due to which the opposite end of the beam acts to seat the release valve I85. After the release valve is thus seated, further downward movement of the stem I82 rocks the beam I84 about its connection with the release valve so that the opposite end of the beam engages the supply valve I86 and unseats same against spring I98. Fluid under pressure supplied to chamber I86 then flows past the supply valve I35 to chambers I8! and I38 and from chamber I8I through pipe i16 to jet 32 in the sanding device 28 and to the cleaning device 2| for effecting operation thereof in the manner hereinbefore described.

It will be noted that there will be a continual venting of fluid under pressure from chamber I8I through the jet 32 in the sanding device 28, but the capacity of supply valve I86 to supply fluid under pressure to chamber I8I exceeds the venting capacity of the jet 32, as a result of which the pressure of fluid increases in chamber I8I and in chamber I86 at the lower side of the diaphragm I11 and when increased to a degree substantially equal to brake cylinder pressure acting in chamber I18, the spring I83 starts moving the stem I82 in an upwardly direction. As the stem I82 is thus operated the beam I84 is also operated to permit spring I98 to move the valve I86 toward its seat so as to reduce the rate of supply of fluid under pressure to chamber I8I to a degree which will maintain the pressure of fluid in said chamber substantially equal to brake cylinder pressure acting in chamber I18. The pressure of fluid thus supplied to the jet 32 in the sanding device 28 will equal that acting in the brake cylinder device 6 and will blow sand through the sanding device to the sand pipe 21 in an amount proportional to said pressure and therefore proportional to brake cylinder pressure and the degree of brake application.

When a reduction in pressure in brake cylinder 6 is effected to compensate for a reduction in the speed of the vehicle said reduction becomes effective in chamber I18 of the relay valve device I15. As a result, the higher pressure in chamber I80 deflects the diaphragm I11 in an upwardly direction which permits spring I83 to elevate the stem I82 permitting closure of the supply valve I86 and then opening of the release valve I85. Unseating of the release valve permits the pressure of fluid acting in chambers IBI and I88 to reduce and when so reduced to a degree slightly less than the reduced brake cylinder pressure acting in the diaphragm chamber I18 the diaphragm I11 is again moved downwardly by brake cylinder pressure and acts through the stem I82 to first seat the release valve I85 and then unseat the supply valve I86 to an amount sufficient to maintain the pressure of fluid in the chamber I8I and in chamber I88 substantially equal to brake cylinder pressure in chamber I18.

In actual practice the release valve I85 may never open under the condition just described since the required reduction in pressure in chamber I88 to effect readjustment of the supply valve iBS to the reduced brake cylinder pressure acting in chamber I18 may occur through the jet 32.

In either case the pressure of fiuid supplied through pipe I18 to the jet 32 in thesanding device 28 is reduced according to the reduction in brake cylinder pressure so that a lower prese sure head is available to blow sand through the sanding device 20 to the outlet pipe 21 for sanding the rail. This results in less sand being supplied to the sand pipe 21 for sanding purposes, and assuming that the reduction in pressure in the brake cylinder device 6 corresponds to the reduction in vehicle speed the amount of sand supplied for sanding is reduced in proportion.

When a further reduction of pressure in the brake cylinder 6 is effected to compensate for a further reduction in vehicle speed, the relay valve device I15 will again operate to correspondingly reduce the pressure of fluid supplied to the sanding device 28 and the amount of sand sup-plied for sanding the rail will be proportionately reduced, as will be apparent.

It will now be evident that if brake cylinder pressure is reduced in proportion to the reduction in vehicle speed in order to provide for instance, a constant rate of deceleration of a vehicle, the sanding of the rails under a vehicle may be controlled by fluid at a pressure which varies in proportion to brake cylinder pressure and provide a substantially uniform degree of rail sanding for all vehicle speeds. In other words, the rate at which sand will be supplied or the quantity of' sand supplied will vary in proportion to the vehicle speed.

At the time the application of brakes is initiated the fluid at brake cylinder pressure supplied to piston chamber 82 in the valve device. 24 moves the piston 8I in a downwardly direction to unseat the valve 85 and to seat the valve 81. This cuts off the supply'of fluid to the timing reservoir 94 and connects said reservoir past the valve86 to chamber 84 which is open to the atmosphere through a choked passage 284." As a result, the pressure of fluid in the timing reservoir 94 acting on piston 93 in the timing valve device for holding the valve I96 open starts to reduce to the atmosphere immediately when a certain low degree of pressure, such as five pounds, is obtained in the brake cylinder device 6. .When the timing reservoir pressure becomes reduced to a relatively low degree the spring 20I in the timing valve device I'M acts to seat the valve I86 and unseat the valve I95 and during such movement moves the piston I83 from the position shown in a downwardly direction.

The closing of valve I96 terminates the supply of fluid at brake cylinder pressure to the relay valve diaphragm chamber I18 while the opening of valve I95 vents said chamber to the atmosphere by way of valve I95 to chamber I91 and then through the vent port I88. When this occurs the pressure of fluid acting in chamber I88 of the relay valve device returns the diaphragm I11 to its normal position shown which permits spring I83 to elevate the stem E82 and thereby operate the beam I 84 to permit closing of the supply valve I86 and opening of the release valve I85. This vents fluid under pressure from chambers I80 and I8! and from pipe I16 to the atmosphere by way of the vent port I81 thus terminating the supply of fluid under pressure to the jet 32 for sanding the track rails.

The size of the timing reservoir 94 is however so related to the venting capacity of the choke 284 that the timing valve device I14 will not operate to terminate sanding, as just described, until a vehicle has been brought to a substantial stop fro-m a maXimum speed with the brakes on thevhicleapplied to a maximum degree, thereby insuring adequate sand for braking during the most severe period of operation, but preventing undue loss of sand which might occur if the timing valve device Hdwere not provided to limit the duration of sanding.

The only function-oi the valve device 24 in this embodiment is to charge the timing reservoir 94 when the brakes on thevehicl are released andto disconnect said reservoir from'the fluid pressure supply pipe IS and to connect same-to the exhaust-port 284 during an application of the brake for controllingthe period of operation of the timing valve device I74 as-just described.

If atany timetheengineerdesires a maximumamount of sand applied'tc the track rail either during braking or acceleration he depresses the brake' valve handle-8a to unseat the sand valve I2 in the brake valve-devicev to supply fluid from the fluid' pressure supplypipe IE to pipe I9 in the samemanner'as above described in connection withFig. 1. The 'flui'd'thus supplied to the pipe!!! flowsthrou'gh'the -double check valve 9! to diaphragm" chamber I18 in the relay valve device I and operates said device to seat the release 'valve' I85 and to unseat'the supply valve I86 past whichfiuid at the pressure in the supply pipe [-5 "will'be. supplied'to pipe I16 leading to the jetr'32 in the sanding. device 20 and 1 to the cleaning "device i'l'whi'ch then operate to provide a maximumflow of sand'to the sand pipe 21 for sanding the rail. Since. the pressure of fluid supplied by the brake valve device to diaphragm chamber'I'IB equals that which is obtainable past the supply valve [86 in diaphragm chamber I88, the diaphragm I11 will maintain the supply valve I86. in a substantially wide open position to insure that thepressure obtained at the jet 32 int-he sanding device 20 for sand purposes will be substantially the same as in the supply pipe It as will be evident.

Description of embodiment of invention shown in Fig. 7

If desired,'theduration ofthe sanding period by the apparatus shown in Fig. 6 may be controll-ed'by movement of the vehicle instead ofvby the timing valve device I14 and timing reservoir 9d, just described. An apparatus embodying this modification is shown in Fig. '7 of the drawings wherein the reference character 205' indicates an electromagnetdevice which is adapted to be connected'in circuit with the generatoriil associated with the vehicle wheel '29 upon opera- 7 tion of the pneumatic switch device 22 when a certain low pressure is obtained in the brake cylinder device 5, such as five pounds as hereinbefore described in connection with the disclosure in Fig.1.

The electro-magnet device 205 comprises a magnet 266 having one terminal connected to the wire and the other to the wire 59, shown in Fig. 1 of the drawings, andfurther comprises a pair of-oppositely seating valves 25'! and 208. The valve 291 is contained in a chamber'ZflB connectedto the brake cylinder pipeIES while the valve 238 is contained in a chamber 2H1 which is open to'the atmosphere through a ventport 2! I. engage in a chamber 2l'2 .which is open through pipe I9I' and the double check valve device'.91 to pipe I79 leading to therelay valve device I15. A spring 2 I3 is provided in chamber ZGQ' for seating valve 201 *andfor unseating valvefifla.

The two valves have fluted stems which a tated Operation of embodiment of invention shown in Fig. 7

Inoperation,whenever. fluid under pressure is suppliedtoLthe brake cylinder device 6 to apply thebrakes on the vehicle'the pneumaticcylinder deviceiZ is operated to move the contact 65 into circuit closing relation with the contact fingers 63 and so as to connectthe magnet 285 into circuit with the generator 6i.

The magnet 206 is thereby energized and operates to seat valve (208 and unseat valve 201 whereupon fluid at brake cylinder pressure flows from-pipe :69 through chamber 289 past valve 201 to chamber .2I2 and thenthrough pipe I9I, double check valve device 91 and pipe I19 to the relay-valve device H5. The relay valve device I then' operates as hereinbefore described to supply fluid at a corresponding pressure, to the Sanding device 20 for effecting operation thereof to provide a proportionate flow of sand to the track rail for sanding same. As thebrake cylinder pressure is reduced the relay valve device I15 willoperate-to reduce the pressure of fluid supplied to the sander device 20 and thus correspondingly reduce the amount of sand applied to the track railfor sanding in the same manner as in the embodiment of the invention shown in Fig. 6.

The supply of sandior sanding the track rail may be terminated in this embodiment of the invention eitherby. the reduced output of generatorfil at the time the vehicle is substantially stopped or by-brake cylinder pressure reduced to a low degree at this time,--as-will now be described.

When the vehicle becomes substantially stopped, the output of the generator 6| will be insuflicient to maintain the magnet 286 energized, asa result of which spring 2I3 will seat valve 201 and unseat valve 208. The supply of fluid from the brake cylinder device to therelay valve device I15 will-be thus cut off and diaphragm chamber I18 in said'relay valve device vented to the atmosphere past the valve 208 and through the vent passage 2| I. The relay valve device will then operate as hereinbefore described to out off the supply of fluid under pressureto the sanding device 20 to thus terminate sanding of the rail. In case the pressure of fluid in thebrake-cylinder device 6 should'become reduced sufficiently low before the output of generatorfii becomes reduced sufllciently to terminate sanding, then the pneumatic switch device 22 will operate to'open the circuit through the magnet 2% and terminate sanding. The primary purpose of the pneumatic switch device 22 is however-to open the circuit through magnet 265 at all times except during braking.

If, in this embodiment, the-vehicle wheel to which the generator BI is connected should cease to rotate at any time during braking the magnet valve device 205 will operate to out off the supplyof fluid under pressure to the'relay valve device I15 which in turn will cut off the supply of fluid under pressure forblowing sand to the track rails; so as to thus prevent excessive abrading of the vehicle wheel during such sliding. In case the vehicle wheel should subsequently start rotating-again, sanding ofthe-rail will again occur, as will be apparent.

Description ofembodiment of invention shown in Fig. 8

Inlthe embodiment of the invention shown in Figifi'the amount of sand supplied for sanding

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