US1622430A - Electropneumatic brake - Google Patents

Description

l March 29, 1927. c, FARMER ET A'- ...JECTROPNEUMATIC BRAKE mea May 27, i926 Patented Mar'. 29, (1)927.

. UNITED' STATES PATENT OFFICE.

emma o. ranura, or rrrrsnunen, bANnJosnmrc. noo-UNE, on nnenwoon, rmsYLvANIA, AssIGNoBs To THE wEsrINGnoUsE am BRAKE contraluz, or wn;-

HEVBDING, PENNSYLVNIA, A.' CORPORATION 0F PENNSYLVANIA.

" ELECTBOPN-EUMATIC BRAKE.

Application nled lay 87, 1926.. Serial No. 111,995.

This invention relates to safetycar control equipments', and the principal object of our invention is to provide an im roved and s1mplified electro-pneumatic sa ety car control 5 equipment.

In the accompanying drawing, the single ligure is a diagrammatlc view of a safetycar control equipment embodying our invention.

` As shown in the drawing, the e uipinent l .may comprise a. brake switch, at eac end ofthe car havin the'operating positions designated as re ease, lap, and service, and a foot controlled switch device at each end of the car comprising a push button 1 and a l switch member 2 adapted to 'be operated by said button.

The equipment also includes an emergencyv valve device`3, a brake cylinder 4, a main res-v ervoir 5, a release magnet 6, a service magnet 7, an emergency magnet 8, a cut-oli switch switch device 10.

The emergency valve device 3 comprises a casing havinga piston chamber 11I connected to a control pipe 12 and containing a piston 13 and a. valve chamber 14 connected to the main reservoir 5 through pipe 15 and containinga slide valve 16 adapted to be operated by 'piston 13. l t In dperation,.with -the push butto'n l held depressed, the switch member 2 closes a cir'. cuit from a current supply wire 17 to a wire v18 which is connected to the emergency mag# l net 8. Said `magnet is thereby energized 'and operates double beat valves 19 `and 20, so that valve 19 is seated, cuttingoif communication from control pipe 12 to an atmospheric exhaust port 21, and valve 20 is unseated, permitting Huid under pressure to be supplied fromn the main` reservoir pipe- 15, through` a restricted port 22, tothe control pipe 12. Pgistonchamber 11 being thus charged witli fluid at main reservoir pressure andthe valve-chamber 14 being connected to the main reservoir, the piston 13 will be shifted to normal release position, due to the diiierential impressure which is createdby the small piston 23 being donstantly subject to atmospheric pressure. With 'the .brake switch inu release position, the current supply wire 17 is connected to devicev 9, and a, holding coill controlling unseated and il id under wire 24, which leads to release magnet `6, so

that said magnet is energized and operates to'hold the release valve 25 unseated. The

ap lication magnet 7 is deener ized, and the va ve 26 is therefore permitte to seat. The

releasevalve 25 being o en, the brake'cylinder 4 is connected to te exhaust, through pipe27, passage. 28, cavity 29 in emergency ,Slide valve 16, passage '30, pipe 31, and past valve 25 to eghaust port 32.

The cut-oil switch device 9 comprises a cas- 1 in containing a piston 33, connected on one., si e to a pipe 34, leading to pipe 31 and said piston is providedvwith a stem 35 Vcarrying a contact member 36 adapted'to controla circharged with fluid under pressure, the piston 38 is forced to its upper position,' in

which the switch member 40 closes a circuit,

to a holding coil (not shown) which maintains the powercircuit. y j

' An application of the brakes may be effect-y ed by moving the brake switch to service zipbrake cylinder,-

plication position, in which the fcurrent supply wire 17 is connected to wire 41, which leads to the applicationmagnet 7. Said magnet being thus energized, the valve 26 is ressure is vented from one side of al relay valve 42 through passage 43, past valve 26 to .passage 44,

which is open to the brake cylinder 4. The relay valve'42` is then movedupwardly byv fluid at main reservoir pressure acting on the outer lower area of said-valve and there by the mainl reservoir pipe 45 is connected to passage 44; so that fluid from the main reservoir is supplied to the brake cylinder through pipe 31, cavity 29 in slidevalve. 16, passage 28, and pipe 27. The release vmagnet 6 is deenergized 1n the service application popressure be increased to a predetermined sition of the brake switch, so'that the valve 25 is permitted to seat and prevent the esca e of liuid from the brake cylinder.

llVhen `a. service application of the brakes is effected, iuid under pressure is supplied from the pipe 31, throu h pipe 34 to cut-oft' switch piston 33, and i? the brake cylinder amount, said piston will be shifted upwardly to cause the switch member 36 to close a circuit from supply wire 17 to emergency magnet wire 18.

'It will thus be evident, that if a service application of the brakes is effected, the foot button 1 may be released without causing the emergency magnet 8 to be deenergized. i

If the brakes are not applied and the motornian should release the foot button 1, either accidentally or by design, the circuit of the emergency magnet 8 will be opened, permitting the double beat valve 2O to seat and the valve 19 to unseat. The unseating of valve 19 permits fluid under pressure from the control pipe 12 to be-vented to the exhaust port 21 and the reduction in control pipe pressure thus produced, causes the emergency piston 13 to be shifted to its outter position by fluid under pressure in valve chamber .14. The slide valve 16 is thus moved to emergency position,in which passage 28 is opened to valve chamber 14, permitting fluidunder pressure to flow from said,7 valve chamber and consequently the main reservoir 5 to the brake cylinder 4, so as to cause an emergency application of the brakes. u

The venting of fluid from the control pipe 12 also reduces the pressure on piston 38, permitting spring 46 to shift the piston 38 to its lower position and thereby causing the switch member 40 to open the circuit of the holding coil. The holding coil being thus deenergized, the power circuit is opened.

. The brakes may be released after an emergency application of the brakes, by depressing the foot button .1, `whereby the emergency magnet 8 is again energized, so as to effect the closure of valve 19 and the opening of valve 20'.' Fluid-under pressure is then supplied from the main reservoir to the control pipe 12 and the emergency piston 13 is returned to release' position, in which the brake cylinder 4 is connected to the atmosphere, as hereinbefore explained.

The piston 38 is also moved upwardly by fluid under pressure in the control pipe 12, so as to close the circuit to the holding coil and thus effect the closing of the power circuit.

When the motorman goes from one end of the car to theother, he can prevent an emergency application of'the brakesupon release of the push button 1, if he makes ,a service application of the brakes of a predetermined amount, and when he is at the other end of the car he can release the brakes by pressing down the push button 1, so as to close the circuit to the emergency magnet 8 and by moving the brake switch to release position. The brakes will then be released, as hereinbefore described.

A conductors valve 47 connected to' the control ipe 12 may be installed in the cab, so that t e motorinan may operate said valve to vent air from the control pipe to eiiect an emergency application of the brakes, in case of possible failure of the electric control. A similar conductors" valve 48,1 may be provided for control by the conductor, in case the conductor or a passenger should find it necessary to effect an emergency application of the brakes.

Having now described our invention, what we claim as new and desire to secure by Letters Patent, is

1. In a safety control equipment, the combination withv a control pipe and an emergency valve device operated upon a reduction in fluid pressure in said pipe for effecting an application of the brakes, of a valve for ventin fluid from said pipe, a magnet for operating said valve, a foot controlled switch for controlling the circuit of said magnet, and a switch device operated upon an a plicatiton of the brakes forl controlling the circuit ofisaid magnet.

2. In a safety control equipment, the combination with a control pipe and an einergency valve device operated upon a reduction in fluid pressure in said pipe for effecting an application of the brakes, of a valve for venting fluid from said pipe, a magnet adapted upon deenergization to open said valve, a foot cntrolledswitch operative upon release for opening the circuit of said magnet, and a switch device operated upon fapplying thebrakes for closing'the circuit to said magnet.

3. In a safety control equipment, the combination witha control pipe and an einergency valve device operated upon a ,reduction in fluid pressure in said pipe for effecting an application of the brakes, of a valve for ventin Huid from said pipe, a valve for supplying fluid under pressure to said pipe, and a magnet for operating said valves. j

. 4. y In a safety control equipment, the combination with 'a brake cylinder, a control pi e, and a valve device operated upon a reduction in iluid pressure in said pipe for effecting an emergency application of the brakes, of a valve for ventin fluid from the control pipe, a magnet a apted' upon deener ization for opening said valve, and a switc device operated upon a predetermined increase in pressure in the brake cylyinder for closing'a'circuit to energize said magnet.

5. In a safety control equipment, the combination with electrically controlled means for controlling the application of the brakes and a brake switch device for controlling 5 said means, of a control pipe, means operated upon a reduction in pressure in said pipe for effecting an emergency application of the brakes, a valve for venting fluid from said pi a magnet for operating said valve,

and a I oot controlled switch for controlling l0v the circuit of said magnet. p

In testimony whereof :we have hereunto set our hands. l v

` CLYDE c. FARMER.

JOSEPH c. MCCUNE.

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