US2232914A - Rail sanding control means - Google Patents

Description

Feb. 25, 1941. E E, HEWITT 2,232,914

I RAIL SANDING CONTROL MEANS Filed Sept. 2.9, 1939 2 Sheets-Sheet l Feb. 2s;- 1941. E, E, Haw," 2,232,914

RAIL SANDING CONTROL MEANS Filed Sept. 29, 1939 2 Sheets-Sheet 2 INVENTOR ELLIS E .HEWITT ATTORNEY Patented Feb. 25, 1941 UNITED STATESv PATENT" QFFICE' nant s-ANDINGcoN'rRoL MEANS Application September 29, 1939, SerialNo; ,297,121l

12Y Claims.

forv a limited period of time, the length of` which` n is usually predetermined so as to. approximate the interval normally required in stopping the train` after it has attained maximum speed. With` suchsanding apparatus, an application of the brakes on a train traveling.y at a low speedv may bey accompanied` by automatic operation. of`

the sanding apparatus to supply sand for too long a period, it having` `been found in practice thatV sand may continue to flow to the rails for i one-half to three-quarters of a minute after the train has been brought toastop frorna relatively loW speed.' This is obviously an unnecessary waste of sand.

The principal object of vmy invention i'sto'provideian improved vsandingi control, equipment controlled-in accordance with the speed of the vehicle, and which isl automaticallyT` operative upon initiation of an -a}.'rplication ofthe brakes to effect supply of sand to the railsv inthe usual; manner while the vehicle istraveling ata speed" 3,9 above a predetermined minimum speed, and thenA operative upon reduction of the vehicle speed below said minimum speedto continueltlfiesup-A ply'of sand for onlya predetermined andrela-V tively short interval of time.

35I Another object of the invention ishto 1 provide a sanding control apparatus of the above type which is adapted tof be associated with'` an air brakeequipmentof the class-including speedconn i trolfmeans, together with means operatively intim terlocking the sand control means with the speed co-ntrolled portion of the brake system;

Other objects andadvantages of theinvention will be apparent4 inthe following description: thereof, taken in connection with the; accom-m 45j, panying-i drawings, in which Fig.` 1' is a diagrammatic sectionalivie'w ofA a rail sanding control apparatus constructed'` in` accordance with the invention,` andthe associated parts of a fluid pressure 'brake equipment;4

50i and.

` Fig; 2 is a diagrammatic sectionalfview in fragmentary form of another formv of sanding apparatus'reinbodying features of the invention;

Apparatus shown z'nFz'g. 1"

controlling ,valve device- Il, whichv is adapted a9@ to.. respondio variationsin the; pressure of fluid" Referring to` Fig. lof the` drawings, the'brake` control and sanding equipment illustrated,come prisesia speedgoverned switch device l0, abrake in acontrol:pipe.l2; a ybrake cylinderldevice: i3,

a sanding` control` device |14; ,andi a sanding selec'` tor device;` I5; Therispeed governedfswitclr: device lll; and brakepontrolling device'l imay befof any suitable" construction and" as illustrated are sub- 5 stantially similar( to; the` corresponding devicese of thefspeed controlledibrakesystem disclosed' in"- the United States Patent 2,140,624, which-was issued December; 20, 1938, to E; E; Hewitt and; assigned to the assignee of the present applica-- tion.-

The` speedy governed switchdevice li'- comprises, a casing 2li having achamber 2| within Whichare mounted'a plurality-of Weights 22, each of WhichIis-*operatively mountedona pin 23 carriedby the head por-tion of a shaft 2li, Whichis.. journaled in the casing. and is adapted to. be driven'.- by a Wheel ofthe vehicle in, accordance withl the speed thereof, The .Weights 22' are adapted to respond tocentrifugal forcev for op- 20 erating. a substantially vertically disposed rod`26" which is. slidably mountedA in a. suitable bore formedqin the, casing 2li, each of the weights 221 having, suitable extensions 2"!` formed' thereon and. adaptedfto, engage. al disk. 29" carried by therodl 2.6.. A coil' spring 30"`is interposedfbetween the disk 29 and thefupperwallof'the chamber" 2l for urging thefrod 26"downwardly`-againsttlie' extensions 2Tof'theweights in opposition to the resultant force produced' when the weights 22l are subjected' toicentrifugal"action; `It Willtlius" be apparent thatthe' ro'd` 26 is adaptedto' be" movedupwardly: as theA speedt of thefvehiclein-i creases.

The upper end offthe rod 26 has operatively" as"- sociatedtherewith' a'pluralityof suitably insue lated switchl contact membersrincludinga con"- tact" member 33'whichA is adapted to engage` a` pair of stationary Contact elements 34; a Contacty member r35-which is adapted-to engagera-pair off stationary contact elements 35, anda contact" member 3B* adapted Atoengage a'pairof contact elements 39. Thel contact member 384s secured to the-end of rod`-25 and the'contact'members- 35 and 33 are slidably-mounted thereon; alspringf 451. 4I i being interposedibetween a collar portionf i2 of the rod and'thelcontact meinber- 35for Yurging that member upwardly toward a circuit-plais-Y ingV position,.and` ai similan spring: lilfibeing interposedrbetween the ,collar portion 423: and"` coni` 51p` tact; memberi33 fory urging the rlatter member:- toward: the;A contact elements 34. An insulated` collar i 4 8^is carried on they rochA 26l ini operative` alignment with the contact! member 35` ffor: move ing said'member'awayrfrorn the 'conta-ct. elements 55 36. upon@ downward movementk of'` the shaft as` hereinafter explained. Similarly; an.- insulated.- collar.l 49 is'. carried `on the rod` 262 for moving.; the i contact. member. 33,` away. fromthe-L contact-A elements 3,4 when. the. rod4 2 tf.' is. moved '.unvrardly.

Associated with the speed governed switch device I0 is a fluid pressure switch 52, comprising a casing having a chamber 53 communicating with the control pipe I2, which chamber is formed at a pressure face of a piston 54 operatively mounted in the casing and subject to the force 0f a spring 55 acting on the piston in opposition to the pressure of fluid in the chamber`53.

Therpiston 54 has a piston rod 56 which extends outwardly of the casing and carries a suitably insulated switch contact member 51 that is adapted for engagement with a pair of contact elements 58. The spring 55 is normally adapted to hold the contact member 51 in circuit-open position as shown in the drawing.

The brake controlling valve device is of a class well known in the air brake art, and is herein described -in detail only to the extent required to explain the cooperative relation of the device with the elements of the sanding control apparatus embodying the invention. The control valve device comprises a relay valve portion 62, which includes a valve mechanism of the selflapping type operative to control the supply and release of fluid under pressure to and from the brake cylinder device I3 as hereinafter explained, a diaphragm portion 63 which includes a plurality of diaphragms selectively operable to control the relay valve portion in accordance with selectively cutting the diaphragms in the portion 63 into and out of operation.

The relay Valve portion 62 of the control valve device includes a casing having formed therein a pressure chamber 10 communicating by way `of a pipe 1| with the brake cylinder device I3 and having mounted therein a discharge valve element 12, which has a stem 13 slidably mounted in suitable bores formed in the casing and is urged toward a seat 15 under the force of a coil y spring 16 for closing communication from the chamber 10 to a discharge passage 11. Also formed in the casing of the relay valve portion 62 is a chamber 80, which communicates by way of a pipe 8| with a normally charged reservoir 82 0r other suitable source of fluid under pressure, and which has mounted therein a supply valve element 84 that is movable into engagement with a seat 85 under the force exerted by a spring 86 for closing communication from the chamber to the chamber 10. The supply valve 84 is operatively mounted in the casing of the relay valve portion for movement paralleling that of the discharge'valve 12, and is provided with a fluted stem assembly 89 slidably mounted in suitable bores formed in the casing.

For operating both of the valves 12 and 84 there is provided a centrally disposed plunger 9|, which has an end portion 92 slidably mounted in a suitable bore formed in the casing and carries a pin 93 having pivotally mounted thereon ayoke member 95, one arm 96 of which is operativelyI connected to the stem 13 of the discharge valve element 12, and the other arm 91 of which yoke member is operatively interposed between the end of the stem assembly 89 of the supply valve member 84 and a stationary stop member 99 carried by the casing and extending into the chamber 10. A coil spring |0| is interposed between a wall of the casing and the end portion 92 of the plunger for urging that member together with the yoke member inwardly, or Itowa'rd the right as viewed in Fig. l. It should be understood that the spring |0| is adapted to exert a greater force than that of the spring 86 acting on the supply valve 84, which is in turn adapted to exert greater force than that of the spring 16 which urges the discharge valve member 12 toward seated position, so that while the plunger 9| is not subjected to a force opposing that of the spring |0I, the latter spring is effective through the medium of the plunger and the yoke member 95, which is fulcrumed at the stop member 99, to overcome the force of the spring 16 and thereby to maintain the discharge valve 12 in its unseated position, while the supply Valve 84 is held in seated position by the spring 86, as shown in Fig. 1 oi the drawings.

The diaphragm portion 63 of the brake controlling valve device II comprises a casing having clamped therein four flexible diaphragms |05, |06, |01 and |08, which are of diierent sizes, the diaphragm |05 being the largest and the diaphragm |08 the smallest, and are disposed in pile relation in operative alignment with the plunger 9| of the relay valve portion 62. The diaphragm |05 is subject to the opposing pressures of fluid in the chamber 10 of the relay valve portion and of fluid in a chamber ||0 communicating with apassage III, and has mounted at opposite facesthereof a pair of follower plates I4, one of which engages the end of the plunger 9| within the chamber 10 of the relay valve portion. A follower plate ||6 is attached to the diaphragm |06 within the chamber ||0 and is adapted to engage the follower plate ||4 of the diaphragm |05. Similarly, follower plates ||1 and ||8 are secured to the diaphragms |01 and |08, respectively, the plate I |1 being adapted for engagement with the diaphragm |06 and the plate ||8 being adapted for engagement with the diaphragm |01 when the elements are in the normal position as shown. Formed between the diaphragms |06 and |01 is a chamber |20. The smallest diaphragm |08 is interposed between a chamber |2|, formed at the side of the diaphragm |01 opposite that exposed to chamber |20, and a chamber |22, which communicates at all times through a passage |23 with the control pipe I2.

The magnet valve portion 65 of the brakecontrolling valve device comprises a casing having mounted thereon high speed, medium speed and low speed magnet portions |30, |3| and |32, respectively, which are selectively controllable inr accordance with operation of the speed governed switch device I0 under different vehicle speed conditions. The magnet valve |30 is adapted to be energized as hereinafter explained when the vehicle is traveling at a speed greater than a predetermined high speed, which may be sixty miles per hour, and controls operation of a pair of connected valve elements |35 and |36, which are respectively disposed in an atmospheric exhaust passage |31 and a chamber |38 which communicates with the passage |23. The valve element |36 is adapted to control communication from the chamber |38 through passage to the diaphragm chamber H0, and is normally urged toward its seated position by the force of a coil spring |4I disposed in the chamber |38. The valve element |35 has a fluted stem |42 which is cooperative with the valve element |36, and is adapted to control communication from the passage to the atmospheric passage I 31.

The magnet |3| is adapted to be energized at `in chamber |52.

vehicle speeds in excess 'of a medium speed'f,.sucl`1"` as' forty-live' miles p'erphour.,and` controls. the.` operationiof a pairof valve elements'. |45 and |451 which` are operatively connected by `means ofi` a iiuted: stem Idil. The vvalve element Ill'isadapted to. be urged toward seated position by the force offa spring IiSAand controls-communication from the passage |23) by way of a chamber I5I' to` apassage |531 communicating with the diaphragm chamber |202 The Valveelement |45" is adapted tobe heldin unseated position when the valve element |55 is` seated,` `and controls communication from the passage |53A to an atmospheric exhaust portl IEil.` i The magnet |321 is -adaptedvito be energized only when the speed of the Vehiclefalls below a low speed; such as twenty'miles per hour, and controls operation of -a double beat Vvalve |51, whichis disposed in a. chamber |58 communieating by way of al passage |55 with the diaphragm chamber I'2i, `the valve being normally held inan upper seated position bythe force of a spring Mil for maintaining communication be` tweenithe chamber |55 and a chamber |52 communicating with the passage I 23. When magnet |5325 is energized, the valve |51 is adaptedtofbe moved toa lower seated position for establish ing communication Afrom the chamber |58 to an atmospheric exhaust passage* |55.

Aocordingto the invention the sanding control devicel comp-risesa casing |10 having formed therein a valve chamber I il within which is disposed a double beauvalve member |12 which' is engageable'with-a lower seat |13 for controlling communication between the Valve chamber and achamber I 15 communicating through a passage E15 with the'supply pipe `8I,'and which ,valve is also cooperative with an upper seat |18 for controlling communication between the chamber 'I1I lancrachamberA |15, which'is connected by way of a passage and pipe It@ with suitable fluid pressure operated rail sanding means, not shown; The double beat valve |12 has a fluted stem |82 which extends downwardly into the chamber I 15, where a spring |33 'is `interposed between the end of the stem and the lower wall off the Ichamber for urging the yvalve toward the upper seat |18 as shown in 1. A uted stem |051 Aextends upwardly from thevalve |12 through va suitable bore "andinto the chamber |15. l

Ani operating piston |81 is slidably mounted in a suitable borel formed in the casing |10 above the chamber |19, as viewed in the drawings, which piston has a hollow stem |38 having operatively disposed in a suitably apertured' bnd thereof a plunger |520 that is urged downwardly towards theflutedstem |55 under the force of "a coil' spring ISI 'contained Within the hollow stem. The piston I-'If has formedat the upper sidelthereoi ai chamber `|92 communicatingl by way of` al branch pipe |93 with` the brake cylinder pipe 11|", andA is subieetgat the opposite side thereoirtothe force of a coilI spring |90 -that is interposed between the pistonand the lower, wall of a chamber |55 formed inthe casing and communicating, with thesanding passage |80. The spring Iil'normally maintains piston |81 in engagement with an annular rib Igfformed with- A gasket |51 is:` disposed in the chamber 1I05fo1 providing a. seal against which `thepiston-i51 isadap-ted to be pressed under'the "pressure offfluid supplied `to the chamber |92, as

hereinafter explained.'

`Thesandingyselectorl `device I comprises a.

"casing 200 having a valveichamber'ZI formed th`erein, in which chamber is; mounted aA slide valve 202", which` is` adapted to be held firmly the valvelchamber. 20| and is. secured toazflexible` diaphragm 20.1 which is` clamped between the casing 20.0 and.' a cover member 208 bolted. or otherwise secured.` thereto.

chamber 20| and on the other sideto the pressureof fluid' in a pressure chamber 2I0, which communicates by way of a passage and pipe 2I| with the passage |59 in the brake controlling valve, device II`. A coil spring 2I2 is interposed between the free end. of the stem 256 and a cap member 2I3 carried by the casing for opposing movement of the valve 202, stem 206 and diaphi-agm 201 under the pressure of fluidi in chamber 2I0.` i Withthe slide valve 202 held in its normal position by the force of theV spring 2I2 as shown in Figill, a cavity 2I5 formed therein establishes communication between av passage 2I6, which communicates by way of a pipe and passage 2|1 with the valve chamber I'1I of the sanding control' 'device I 4, and a passage ZIB, which communicates by way of a pipe 220 with an auxiliary Sanding reservoir 22|. This reservoir is adapted to be chargedwithsuflicient fluid under pressure to provide' limited sanding operation after the vehicleI speed has been reduced below a minimum speed, suchY as twentymiles per hour, as hereinafter more fully explained.

` Operation When the equipment shown. in Fig. l of the drawings is conditioned for operation, fluid underpressure supplied in. the usualmanner to the main reservoir 812 flows therefrom through the supply pipe 8|'.V to the valve chamber 80` of the brakecontrolling valve device II, and also ows through the chamber I151of the sanding control devi'ceIll, past the double beat valve |12, and throughchamber I'lI and pipe 2|.1 tol passage 2I5 in thesanding selector. device 2I5, and thence by way of the slide valve cavity 2I5, passage 2I9, and pipe 220 to the reservoir 22| which is thereby: initially charged with uid under pressure. With the brakes released', the control pipe I2 is connected tothe atmosphere through suitable communications in a brake valve device or other control mechanism, not shown, so that the uid pressure switch 52 is at this time maintained in circuit-open position, the spring 55 being effective through the medium of the piston 54 and stem 55 to hold the Contact member 51 out of engagement with the' contact element 50. With the uid pressure switch 52 in circuit-open position, the magnets |30, |3I and |32 of the control valve device I I are deenergized, andthe sev- .eral valve elements controlled thereby: are consequently positioned asv shown in Fig. 1, from `which it will be readily apparent that each of they diaphragm chambersl IIO, |20 and I2I, togather; with the chamber 2I0of the sanding'selector; device I5 are connected to the respective atmospheric exhaust ports controlled by the valve elements. At the same timethe'chamber I22`in the` brakev oontrollingvalve device is, con.- nected to the atmospherebywway of thepassage lfand' control'pipa I2; while the chamber 10 The diaphragm 201 issubject. on one side toA atmospheric pressure in:

in the relay valve portion communicates past the normally unseated valve 12 with the vent passage 11.

When the vehicle is operated at a high rate of speed, in excess of sixty miles per hour, for example, the elements of the speed governed switch device I assume the position shown in Fig. 1, the shaft 24 being revolved rapidly enough to cause the weights 22 to be thrown outwardly under the effect of centrifugal force, so that the vertically disposed rod 26 is maintained in its uppermost position against the force of the spring 30. With the rod 26 in this position, the contact member 33 is adapted to bridge the contact elements 39, while the contact member 35 similarly bridges the contact elements 36 under the pressure of the spring 4|. At the same time, the collar portion 490i the rod 26 is so disposed with respect to the contact elements 34 as to hold the contact member 33 out of engagement therewith.

If it is now desired to eiTect an application of the brakes, the brake valve device controlling the pressure of fluid in the control pipe I2 is operated in the usual manner to effect an increase in the pressure of uid therein corresponding with the desired degree of application of the brakes. Fluid under pressure thus supplied'to the control pipe flows therefrom through passage |23 in the brake controlling valve device II to the connected chambers |38, II, |62 and |22, while the pressure of fluid in the chamber 53 of the fluid pressure switch 52 is correspondingly increased for moving the piston 54, stem 56 and contact member 51 upwardly until the contact member bridges the contact elements 58. When the fluid pressure switch 52 is actuated to circuit closing position and while the speed governed switch device I0 is maintained in the high speed position as shown in Fig. 1, circuits for energization ofthe magnets |30 and I3I of the brake controlling valve device II are established. The circuit for the high speed magnet |30 includes the positive terminal of a battery or other suitable source of electric power 230, a grounded conductor 23|, a similarly grounded conductor 232 connected to the magnet |30, a conductor 233, the connected switch contact elements 38 and 39, a conductor 235, the contact element 51 and 58, and a return conductor 236 connected to the negative terminal of a battery. 'Ihe circuit for the medium` speed magnet |3I includes the battery 230, the grounded conductor 23|, a grounded conductor 238 connected to the magnet, a conductor 239, the connected contact elements 35 and 36, the conductor 235, connected switch elements 51 and 58 and the return conductor 236.

Upon energization of the high speed magnet |30, the valve elements |35 and |36 are operated thereby against the force of the spring |4| to their seated and unseated positions7 respectively, whereupon fluid under pressure from the control pipe I2 is supplied by way of passage |23, and chamber |36, past the unseated valve |36 and through the passage |I| to the diaphragm chamber |I0 in the brake controlling device II. Similarly, upon energization of the medium speed magnet I3I the valve elements |45 and |46 are moved against the force of the spring |49 to their respective seated and unseated positions, so that uid under pressure is supplied from the control pipe by way of the passage |23, chamber |5I, past the unseated valve |46 and through passage |53 to diaphragm chamber |20. `Since the low speed magnet |32 is' not energized at this time, the double-beat valve |51 remains in its upper seated position as shown, and fluid under pressure is thus supplied by way of the passage |23, chamber |62, chamber |58 and passage |59 to the diaphragm chamber I2I, and also by Way of the -pipe and passage 2II to the pressure chamber 2I0 in the sanding selector device I5.

i The pressure of iluid supplied to the chamber 2 I0 of the sanding selector device I5 acts against the diaphragm 201 to force the diaphragm, the stem 206 connected thereto, and slide valve 202 to the right, as viewed in the drawings, until a follower element 24| carried by the diaphragm engages a stop rib 242 formed on the casing 200. When the slide valve 202 is so operated, a passage 245 formed therein is brought into registration With the passage 2I6 and a passage 246 which leads through a pipe 241 to the passage |16 in the sanding control device I4. At the same time, the cavity 2|5 in the slide valve is moved out of registration with the passage 2|6, but uid under pressure is still free to flow to reservoir 22| from the supply pipe 8| by Way of the passage |16 in the sanding control device, pipe 241, passage 246, slide valve passage 245, passage 2|6, past a ball check valve 250 and through a chamber 25| containing the same, the passage 2I9 and-pipe 220.

Meanwhile, the pressure of uid supplied from the control pipe to the diaphragm chamber IIO of the brake controlling valve device II vacts through the medium of the diaphragm |05 to move the plunger 9| outwardly against the force of the spring IOI, it being understood that the diaphragm |05 is at this time adapted to move independently of the other diaphragms |06, |01 and |08, the opposing fluid pressures on which are equalized, as hereinbefore explained. As the plunger 9| is thus moved outwardly, .the yoke member 95 carried thereby is initially fulcrumed at the point of engagement of the arm 91 with the stem assembly 69, and the yoke member is thus turned about the pin 93 for causing the arm 96 thereof to move the valve element 12 into engagement with the seat for closing the communication from the chamber 10 to the atmosphere. Upon seating of the valve element 12, continued movement of the plunger 9| by operation of the diaphragm |05 is effective to tilt the yoke member 95 in a clockwise direction about the pin 93, the arm 96 of the member being then fulcrumed at the point of engagement with the stem 13, so that the arm 91 of the yoke member is operated to shift the stem assembly 89 and the valve element 84 outwardly against the force of the spring 86, the valve element thus disengaging the seat 85 for permitting flow of iluid under pressure from the supply pipe 8| through chamber 80 and past the fluted stem 89 to the chamber 10. Fluid under pressure thus supplied to the chamber 10 flows therefrom through the brake cylinder pipe 1| to the brake cylinder device I3, which is thereby operated to effect an application of the brakes.

Fluid under pressure is also supplied from the brake cylinder pipe 1| through the branch pipe I 93 to the portion of the chamber |92 of the sanding control device I4 outwardly of the rib |96, and, assuming that brake cylinder pressure is increased suiciently, the piston |81 is then forced away from the rib |96 so as to expose its entire area to the chamber |92, whereupon the piston is shifted downwardly with a snap-like action into sealing engagement with the rubber gasket |91.

The plunger |89..is thereby `brought .into engagementwi'th the 4iluted stem |85 vand through the medium thereof Vmoves the double-beat valve |12 between the chambers andv |19. Fluid 4under pressure is then quickly supplied `fromthe supply .pipe 8| through .passage |16, pipe 241, `passage `Zilli in the sanding `selector device l5,slide valve :passage 245passage2l6 ,and pipe 2|11to chamher .'|1|, and thencepastthe double-beat valve |12 and through .chamber '|19 and passage and pipe .IS' tothe usual .fluid pressure responsive sanding mechanism, notshown. It `willfbe understood that, while the sanding selector .device |5 andthe `sanding control device |4 are maintained y in the operating position to which they have been 4iiuid 'in the -chamber 'l I'IJ.

moved during an application of the brakes while the vehicle is `traveling atr a high speed, as just explained, `thesanding of .the rail is continued at ,a substantially constant rate, since the reservoir Mfrom which iiuid under ,pressure is supplied for the sanding operation ,constitutes a ypractically unlimited source. s

)The brake controllingdevice is automatically operated .to cut off further'supplfy of fluid under pressure to `the "brake .cylinder .device |3 when the pressure of fluid in '.the chamber 1U is increased slightly above "the opposing pressure oi The diaphragm |05 andthe associated plunger 9| 'are thus .adapted to be shifted tothe right as viewedin the drawings,

whenthe combined pressures of fluid in the chamber 1I] Vand Nof "the 'spring `|ll| overbalance the fluid pressure in chamber liti), and Awith the endtt oi theyoke member 95 heldstationary bythe force ofthe spring 1B, the yoke member `is thereby'turned in a 'counterclockwise direction `about the pin'93 fforppermitting the spring to move the supply valve 84 into engagement with the seat 85. Therelay valve'mechanism is thus moved tolap position, wherein both the `supply `valve 84 and thedischarge valve 12 are heldin seated position.

As the speed of the `vehicle reduces, the speed governed switchdevice YIl) is operative to 'control "the `circuits forthe magnet valvefdevices so as to eiect lreduction in the force 'exerted `by vthe several diaphragms in.` the' brake controlling valve device `in controlling `operationo'f the relay valve portion thereof, the degreeof application of the brakes thereby regulated in Ia series oi" steps `or in successively decreasing ratios with respect Ito the control Apipe pressure, fthe ratio of brake `cylinder..pressureto controlpipe pressure fat 4any time being determined 4by the vehicle speed. This .operation 'of the ybrake equipment iis well understoodby thoseslkilled yinthe-art and "is clearl-yeirolaihed in 'the aforementioned Patent 2,140,624. The `rail `sanding `control apparatus associated with the braking "equipment shown in Fig. `1 is `operativeto 'eiect `a constant supply of 'sand to the rails,`1as hereinbefore explained,

throughout the range of `speed of the vehicle so long asthe speed exceeds afpredetermined minpositioned out of engagement .with the contact elements .36, while the .contact member `3`3 is heldy in yengagement with the contact elements '3d under the force of the spring 45. "With the switch contact members 38 and 35 thus disconnected from the respective pairs of contact elements 39 and 36, the circuits for the high and medium speed magnets 13D and |3| are broken, so that the valve spring `|4| is .rendered effective to shift the associated valve elements |36 and 35"to their seated and unseated positions respectively, while the Valve .spring "|43 is similarly enabled to move to the valve elements I 46 and |45 to seated .and unseated positions, as shown in Fig. `1.`

When the valve element is thus moved to unseated position, the diaphragm chamber 'Iltis connected tothe atmosphere by way of the ,passage H l, `past thev unseated valve element, and through the exhaust passage |31. Withthevalve M5 unseated, the diaphragm chamber i129) is connected with the atmosphere through lthe passage |53, past the unseated valve through the exhaust port |54. l

At the same time, since the switch contact member 33 of the switch device I3 now engages the contact elem-ents 34, the low speed magnet |32 is energized through a circuit comprisingthe `positive terminal of the 1battery 233, grounded conductor 23|, a `grounded conductor 2153 connected to the magnet |32, a conductor 2&1, `the aforementioned switch contactelementathe conductor 235, the switch *Contact elements `51 and '58, and the returnyconductor 236 leading to Lthe negative terminal of the battery. lWhen the magnet |32 is thus'energized, the double-beatvalve i |51 controlled thereby 1is Vshifted to its lower seated position against the force of the spring ttl, with the result that'the passage |59 iS-,connected to the atmosphereby way of the exhaust passage 55'fcr ventingthe diaphragm chamber] 2| ofthe brake controlling `device and for also 1venting the pressure chamber 2|0 of the sanding selector device I5, `by way of the `passage and" pipe V2||. It will Ibe apparent, that with 'the vthree .diaphragm chambers` ||'0, |20 and` |2| thus connected 'to thelatmosphere, the relay val-ve mech-L anism of the brake `controlling device |^|-vvil1 lthereafter be controlled -in accordance'` `with variations "in control pipe pressure acting lin `the chamber l2? Vagainst the small diaphragm |38 in opposition to the pressure of fluid in chamber?- rIt actingiagainst the large diaphragm |05.

When the -pres-sure of 'fluid in the chamber 2&0 of the sanding selector device 'I 5 Ais vented to the atmosphere, by reason ofthe above described-operation o`f the' brake controlling device to correspond with the minimum rangeof speedof the vehicle, the spring 2|I2 becomes elective to shift the stem 206, diaphragm 201 andthe slide'valve A202 to the left and linto the position `shown in Fig. 1 of the drawings, so that the valvepassage l 2145 is moved outof registration with "the passages 2|5 and 245 While the cavity 2`|15 onlcegmore is brought 'into registration with ypassages 215 and 2|6.- l\/Iea.nwhile,"the pressure'of uid inthe chamber |32 Aolf the sanding control device i4 is l still effective to maintain the piston |31 .in engagement withthe sealing gasket |91, so that the double-beat valve '|112 is hel-d inengagement with" the lower seat |13 forfmaintaining communication between -thefchambersf`- |i1| and |19, as already explained. Fluid underpressure for operating .the sanding apparatus with which the vehicle is equipped is` `then 'supplied from 'the relatively small reservoir 22| Aby wayof pipe 229,

passage 2 9 in sanding selectordevice |15,valve cavity 215, passage ,2|6,` pipe 2|1, Valve chamber |1| in `the sanding control ldevice I4, past the doublebeat valve |12 and thence through chamber |19 and passage and Ipipe |88. `Since the volume of fluid under pressure initially stored in the reservoir 22| is suiicient to continue sanding of the rails for an interval -of time approidmating that required to bring the vehicle to a stop from a speed of about 20 ,miles per hour, it will be apparent that adequate sanding of the rails is thus obtained Without undue waste of sand and fluid under pressure.

When the release of the brakes is effected by reduction of .the pressure of fluid in the control pipe |`2 in the usual manner, .the consequent reduction in the pressure of fluid in the chamber |22 acting on the diaphragms in the control valve device results in complete withdrawal of force opposing tha/t of the fluid pressure in chamber 18 as aided by the force of spring |8I, so that the relay valve mechanism is actuated to effect seating of the valve 84 and unseating of the exhaust valve 1'2. Fluid under pressure is thus ven-ted from the brake cylinder device |3 and from the chamber |92 of sanding control device connected thereto. The spring |94 is then rendered effective to shift the piston I81 upwardly into engagement with the rib |96, while the plunger element |89 is withdrawn from .the fluted stem |85 to permit the spring |93 lto shift the double-beat valve |12 into its upper-seated position as shown in Fig. 1. The elements of the several brake control and sanding control devices shown in Fig. 1 are then disposedin the normal posi-tions as illustrated.

Apparatus shown in Fig. 2 of the drawings Referring to Fig. 2 of the drawings, the brake 0 controlling equipment including the brake controlling device is illustrated in fragmentary form in association with a sanding control apparatus constructed in accordance with a different embodiment of the invention. Included in 45 the sanding control apparatus equipment are a sanding selector device 210, a low speed sanding control device 21|, and an auxiliary sanding resery-oir 212. The brake controlling device is of the same construction as that shown in Fig. 1 and already described, and has formed therein the passage |59 which is adapted to be supplied with fiuid under pressure from the control pipe, not shown in Fig. 2, .when an application of the brakes is initiated, and .to be vented to the at- 55 mosphere upon reduction of the speed of the vehicle below the predetermined minimum speed, such as 20 miles per hour.

The sanding selector device 218 comprises a casing 215 having a .bore in which is operatively mounted a ypiston 216, which is subject on one side to the pressure of fluid in a chamber 211 communicating by way of a passage and pipe 218 with the passage |59 in the brake controlling valve device On .the side of the piston 216 `opposite the chamber 211 is formed a chamber 280 containing a coil spring 28| which is interposed between the lower wall of the chamber and the .piston 216 for urging it upwardly into engagement with an annular seat rib 283. The Seat rib 283, like the similar rib |96 of the sanding control device |54 shown in Fig. 1 of the drawings, is adapted when engaged lby the piston to provide an outer-seated area thereof initially exposed to the pressure of fluid supplied through the pipe 218 as hereinafter explained, and an in ner-seated area which becomes exposed to the ffuid pressure upon downward movement of the piston. Mounted within the chamber 288 is a flexible sealing diaphragm 28-5 which is adapted to be engaged by the piston 216 upon downward movement thereof.

The piston 216 has a hollow stem portion 281 slidably mounted in a suitable bore and carries a movable plunger 288 that is urged downwardly and outwardly of the stemunder a force of a coil spring 289. The plunger 288 extends into a valve chamber 29| containing a valve element 292, which is operatively aligned with the plunger 288 and has a fluted stem 293 mounted in a suitable bore and projecting into a lchamber 294 formed in the casing. The stem 293 operatively engages a similar fluted stem 295 of a valve 296 that is mounted in a valve chamber 291 communicating through a ,passage 298 with the supply pipe 8|. A coil spring 300 is interposed between the valve 296 and the lower w-all of chamber 291 for urging that valve and .the companionV valve 292 into their seated and unseated positions, respectively, as shown in Fig. 2. The valve 296 and valve 292 are adapted to control communication from the respective chambers 291 and 29| to .the intermediate chamber 294, which is connected by way of a passage and pipe382 with the usual fluid pressure responsive sanding means, not shown.

The low speed sanding device 21| is somewhat similar in construction to the sanding selector device 218, and comprises a casing 385 having a bore in which is slidably mounted a piston 386 which is normally urged upwardly by the force of a spring 381 into engagement with an annular rib 388 that is formed on the casing within a chamber 389 communicatng through the branch pipe |93 with the brake cylinder pipe 1|. The spring 381 is disposed in a chamber 3| l, within which is mounted a sealing gasket 3|2 adapted to be engaged by the piston 396 on downward movement thereof under the pressure of iiuid admitted to chamber 389, as hereinafter explained. The piston 386 has a hollow stem 3M having operatively mounted in a suitable bore formed in the lower end thereof a plunger 3|5, the end of which is urged into a chamber 3|1 of the casing under the force of a coil spring 3|8 contained within the hollow piston stem 3|4.

The casing 385 also has formed therein a valve chamber 320, which communicates through a Suitable bore with the chamber 3|1 and through a passageand pipe 32| with the sanding reservoir 212. The chamber 328 contains a doublebeat valve 323, which has one i'luted stem 324 slidably mounted in the bore between chambers 328 and 3|1 and extending into` operative alignment with the plunger 3|5, and another iiuted stem 325 slidably mounted in a bore that communicates with the chamber 328 and with a chamber 326 formed in the casing. The chamber 326 communicates by way of a passage 321 with the supply pipe 8|. A coil spring 321 is interposed between the wall of chamber 326 at the end of the fluted stem 325 and acts through the medium of the stem to urge the double-beat valve 323 toward its upper-seated position, as shown in Fig. 2, in which position the valve closes communication between the chamber 328 and chamber 3|1 while maintaining communica- -erated in i the usual manner "to'feifect amapplieaf tion 1f o'f y"the f brakes while ithe fvehicle fis {traveling at a speed 4in excessfof 'F20 `miles per hour, fiiuid lunder pressure is supplied in the manner already explained through fthe passage 4|59 lin fthe -control Vvalve idevice, and lthence through pipe Iand passage V21B tothe chamber `211 of `the-sanding selector device 210. Thepiston 216isthere by moved downwardly against the iforce of the spring 28| `to Acause plunger 1288 to Iengage the valve 'element 292. "Continued downward movement-of the piston 216 then effects seating of the valve `element 292 "for-closing -communication between chambers 29| `and 294, and at thesame time .moves `the valve element 1296 `from its 'seat `against the :force of spring A300. Withthevalve 296 unseated, "fluid under lpressure "is 'supplied ,from the main reservoir '82 "by way 'of the rsupplypipe 8|, passaget298, chanrber291, past the `unseated valve, and through chamber 294 l:and passage and pipe 302 to the fluid pressure 'sand- 'ing means carried by the vehicle. Meanwhile, the brake controlling device is operated inthe usual manner yto effect supply underjpressure through the ,pipe 1| to the brake cylinder device f3 for effecting Ithe application 'ofthe'brakes to a degreecorresponding withthe speed Vof the vehicle. Fluid under pressure at the same time flows from thebrake cylinder pipe 1| vthrough thebranch Apipe |93 Vto, 'the `chamber 309 in the valve device 21|, yand effects quick operation o'f the piston 306 andplunger `3|5 earriedfthereby tocause movement ofthe .double- Ibeat valve element 1323 toits lower-sated posi- 1 however, .that the fluid underpressure with which the sanding reservoir 212 has previously been `charged remains bottled .up-'therein `and in the connected chambers 320, V3I-.1 i and .chamber l29| ofthe sanding selectordevice 210, so longaslthe `valve `element 292 remains seated.

lWhen the speediofthe vvehicle-has been reduced Ltolbelowthe minimum speed of y20nliles per hour,

the brake controlling'valvedevice is automati- 'cally operated in the `manner :already explained to vent the passage 459, and with it'the pipeand passage 1218 `and the piston `'chamber 2'11 :of fthe ftions. n itc itsfseated position, communication fromthe sanding .selector device 2110, `and thelspring 28| thus'becomes effective tomovethepistonZ'lS-and plunger 288 upwardly =to the positionfshown :in

Fig. 2, so that the spring 300 iis .permitted `to movefthe associated yvalve elements 1296fand292 to their respective seated rand unseated riposi- Upon movement 'of the'valve :element y"296 supply pipe 8| to the sanding means "byway 4of the passage `and pipe 302 is'cut off, while 1Aiiuid `under pressure is supplied^from the sandingres- 'ervoir 7212 by way of pipe "and passage l32|,"tlf1eV connected chambers `32`0and `3|1 ofthe low speed sand valve deviee,21|, through `a passage and pipe 333 and a passage 334 to the valve chamber 29| Ain the sanding selector 'device 210, `and then past the unseated valve 292 and through passage rand pipe 302 to the sanding means, lnot shown. As in the 'case of the reservoir, 22| shown in Fig. 1 of the drawings, the rsanding reservoir 212 has suicient capacity to insure adequate supply of fluid under pressure to the sandv ing -means during the intervalof time vrequired tof-bring thevehicle to aIsto-p from the relativen7 low speed of twenty miles per hour.

From theforegoing description, it will be evi- Vdent that an improved sanding control apparatus'constructed in accordance with Ythe invention may readily be designed for cooperation with Yany desired type of speed controlled fluid pressure mechanism, such as that included in a brake equipment for high speed trains, and that by reason of the automatic operation of the appara- 'tus to effect unlimited sanding of the rails while the vehicle is traveling at a speed in excess of a predetermined speed so long as the application of the brakes is continued, and to effect sanding of the rails for a limited interval of time when the brakes are applied while the vehicle is moving at a lesser speed, substantial economies in the use of sand and fluid under pressure are insured.

`While two embodiments of the invention have beendescribed in detail, it is not intended to limit the invention to those embodiments or otherwise than by the terms `of the appended claims.

Having now described my invention, what I claim as new and desire to secure by LettersPatent, is:

1. In `a vehiclecarried sanding equipment, in

combination, a primary sanding control means loperableto eilect sanding, a secondary sanding `control `means operable to eiiect sanding, and

yspeed responsive rmeans operative to condition said primary sanding control means for sanding operation while the vehicle is moving at a speed vin excess of a predetermined speed, and to condition said secondary sanding control means for sanding operation while the vehicle is moving at l`a slower speed.

`2. In a vehicle carried sanding equipment, in

combination, a `primary sanding control means adaptedfor continuous operation, a limited sanding control means adapted for operation for a predetermined interval of time, and speed responsive means operative to condition said primary sanding control means for operation while the vehicle is moving Aat a speed in excess of a predetermined speed, and to condition said limlited sanding control means for operation while they vehicle is moving at a lower speed.

3. A sanding control apparatus for a vehicle equipped with iiuidpressure brake means, comprising primary sanding vcontrol means operative to eiect continuous sanding, secondary sanding controlmeans operative to eiect sanding for a limited ,period oftime, and means controlled bysaidfluid pressure brake means and selectively cooperative with both the primary and the secondary sanding control means for effecting sanding` operation during application of the brakes.

4. A Asanding control apparatus lfor a vehicle equipped'with nuid pressure brake means, com- `prisinggprimary sanding control means operative `toA effect continuous sanding, secondary sanding vcontrol means `operativeto effect sanding for a limited period of time, and means responsive to anjapplication .of the brakes nrst to initiate operation of said primary lsanding control means 'and jthen tostop operationtherecf while causing .operation of said secondary sanding control means. v Y n n V5.1i sanding control `apparatus for -a `Vehicle #equipped with fluid pressure vbrake means and fluid pressure sanding means including a sand pipe adapted to be supplied with fluid under pressure during sanding operation, said control apparatus comprising sanding valve means operative in response to an-application of the brakes to effect continuous supply of fluid under pressure to said sand pipe, and sanding selector means responsive to a certain operating condition of the Vehicle for closing the communication through which said sanding valve means supplies fluid to said sand pipe while initiating a limited supply of fluid under pressure to said pipe.

6. A sanding control apparatus for a railway vehicle equipped with fluid pressure brakes comprising, in combination, fluid pressure responsive sanding control means, means providing a constant supply of fluid under pressure, means providing a limited supply of fluid under pressure, and sanding selector means controlled in accordance with the operation of the fluid pressure brakes for effecting the supply of fluid under pressure tothe fluid responsive sanding means from said constant supply source at one time, and from said limited supply source at another time.

'7. A sanding control apparatus for a railway vehicle having fluid pressure operated sanding means and fluid pressure brake means controlled according to speed, comprising a primary source providing a constant supply of fluid under pressure, a secondary source providing a predetermined limited supply of fluid under pressure, and means conditioned during an application of the brakes when the vehicle is moving at or in excess of a certain speed to effect supply of fluid under pressure from said primary source to said sanding means, and otherwise conditioned to effect supply of fluid under pressure thereto from said secondary source during an application of the brakes when the vehicle speed is less than said certain speed.

8. A sanding control apparatus for a railway vehicle having fluid pressure operated sanding means and speed controlled fluid pressure brake means, including a control communication that is charged with fluid under pressure when an application of the brakes is effected while the vehicle speed exceeds a predetermined value and vented when the vehicle speed is less than such value, said sanding control apparatus comprising a primary source providing a constant supply of fluid under pressure, a secondary source providing a predetermined limited supply of fluid under pressure, a movable abutment subject to the pressure of fluid in said control communication, and valve means controlled by said abutment and operative upon an increase in said fluid pressure to establish communication from said primary source to said fluid pressure operated sanding means, and operative upon a reduction in fluid pressure in said control communication to establish another communication from said secondary source to said Sanding means.

9. A sanding control apparatus for a railway vehicle having fluid pressure operated sanding means and speed controlled fluid pressure brake means, including a control communication that is charged with fluid under pressure when an application of the brakes is effected While the vehicle speed exceeds a predetermined value and vented when the vehicle speed is less than such value, said sanding control apparatus comprising a primary source providing a constant supply of iiuid under pressure, a secondary source providing a predetermined limited supply of fluid under pressure, sanding selector valve means subject to the pressure of fluid in said control communication and operative upon an increase therein for establishing communication from said primary source to said fluid pressure operated sanding means, and upon reduction of the fluid pressure in the control communication to establish another communication from said secondary source to said sanding means, and auxiliary valve means also controlling said communications to the uid pressure operated sanding means and operative to maintain said communications closed while the iluid pressure brakes are released.

10. A sanding control apparatus for a railway vehicle having fluid pressure operated sanding means and speed controlled fluid pressure brake means, including a control communication that is charged with fluid under pressure when an application of the brakes is effected while the vehicle speed exceeds a predetermined value and vented when the vehicle speed is less than such value, said sanding control apparatus comprising a primary source providing a constant supply of Y fluid under pressure, a secondary source providing a predetermined limited supply of uid under pressure, control valve means normally positioned to supply fluid under pressure from said primary source to said secondary source and operative during an application of the brakes to supply fluid under pressure from said secondary source toa chamber, and selector valve means subject to the pressure of fluid in said control communication of the brake means and operative upon anl increase in said fluid pressure to establish communication from said primary source to said fluid pressure operated sanding means, andupon a reduction in the fluid pressure in said control communication to establish communication from said chamber to said fluid pressure operated sanding means.

11. A sanding control apparatus for a railway vehicle having fluid pressure operated sanding means and speed controlled fluid pressure brake means, including a control communication that is charged with fluid under pressure when an application of the brakes is effected While the vehicle speed exceeds a predetermined value and vented when the vehicle speed is less than such value, said sanding control apparatus comprising a primary source providing a constant supply of fluid under pressure, a secondary source providing a predetermined limited supply of fluid under pressure, sanding control valve means operative when the brakes are released to effect supply of fluid under pressure from said primary source vto a chamber and operative during an application of the brakes to establish communication from said chamber to said fluid pressure operated sanding means, and sanding selector valve means subject to the pressure of fluid in said control communication of the speed controlled brake means and operative upon an increase of said fluid pressure to establish communication from said primary source to said chamber in the sanding control valve means, and upon a reduction in the fluid pressure in said control communication to establish communication from said secondary source to said chamber.

l2. In a vehicle carried sanding equipment, in combination, a primary sanding control means operable to effect sanding, a secondary sanding control means operable to effect sanding, and speed responsive means for sequentially effecting sanding operation of said twosanding control means.

ELLIS E. HEWITT.

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