US1994182A - Fluid pressure braking apparatus - Google Patents

Description

March 12, 1935. T. TARISIEN 1,994,182

FLUID PRESSURE BRAKING APPARATUS Filed Aug. 4, 1933 INVE N TO R THEOPHILEI TARISIEN ATTORNEY Patented Mar. 12, 1935 PTATENTYYOFFIQE 1,994,132 a FLUID PRESSURE BRAKING APPARATUS: 1 Theophile Tarisien, Livry-Garg an, France; as-

signor to Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application August 4, 1933, ScriaLNo. 685,586

In Great Britain August 13 1932 6 Claims. (01. 303-8 1) This invention relates to fluid pressure brak ing apparatus of the kind comprising atriple or other form of distributing valve device adapted to effect the application of the brakes by the 5 supply of fluid under pressure to the brake cylinder or' cylindersof the apparatus in two stages,

during the first of which the supply of fluid is relatively unrestricted so as to cause a rapid application of the brake blocks to the wheels, while during the second stage the flow of fluid to the brakecylinder or cylinders is relatively restricted so as to cause a gradual building up of thed'esired pressure.

Distributing valves of this character as hitherto constructed have usually comprised a regulating valve interposed inthe path of the flow of fluid to the brake cylinder or cylinders, this valve being normally maintained in its open position by an abutment subject on one side to the action of a controlling spring. The opposite sideof the abutment is arranged to be subject to the pressure obtaining in the brake cylinder, so that, as soon as this pressure has built up to a value suifi cient toovercome the action of the controlling spring the abutment is moved to permit closure of the regulating valve, the subsequent. flow of fiuid under pressure to the brake cylinder taking place througha relatively restricted port.

The invention has for its principal object to provide an improved regulating valve of the character above indicated in which the abutmentoi the valve is arranged to besubject to a controlling fluid pressure which is a definite predetermined'fraction of the normal fluid pressure ch- 35 taining in the system, thus dispensing with'the use of a controlling spring as has hitherto been customary. I

In order that the invention may be readily understood a preferred embodiment thereof will now be described with reference to the accompanying drawing as applied to V a triple valve device of otherwise known construction.

Referring now to the single figure of'the accompanying drawing, the triple valve comprises 45 a casing 1 containing a valve chamber 2 and a piston chamber 3, the latter containing a piston 4 adapted to actuate a slide valve 5 provided with the usual ports and cavities and containing a graduating valve 6. Mounted on one side of the casing is an accelerating bulb or chamber 7 which communicates through a passage 8 with a port 9 in the seat of the slide valve. In the release position of the triple valve piston, as shown in the single figure of the drawing the port 9 is arranged 55 to be in communication with the atmosphere by hereinbefore and a port 31 in the slide valve seat way of. a cavitylO in the slide valve 5 and an atmospheric-port 11. The valve chamber 2 is in open communication with the-auxiliary reservoir (not ShOWIliiIllth drawing) in the usual manner, the piston-chamber 3 being: in communication 5 with the trampipe 24 of the apparatus. A port 12 in the triple valve casing =1 communicates with thebrake cylinder (not shown in the drawing) and the 'said casing'is providedwith a rotary plug cock"13 having-a calibrated-orifice 14 therein. 10 Arranged below theiplug cock 13 is a controlling valve '15'which is normally open, and the seat 16 of the said controlling v'alve is provided with arestricted by-pass'orifice l'l.

V The controlling valve 15 is arranged to be norl5 mally maintainediniits open position by means of-- a-diaphragm l8 subject onits'uppe'r side to communicating with the brake cylinder, the diaphragm 18 being subject on its lower side normally 1 to the fluid pressure obtaining a diaphragm chamber 21 which under release conditions as shown in the single figurei of'the drawing is in communication-through a passage 22 in the triple Lvalve casing 1 and aport 23 in the slide valve seatwith the slidevalve chamber 2.- Under a'pplication. conditions the. diaphragm' chamber 21 l is in communication with an expansion chamber 30,

25 through passages 22 and 26 in thetriple valve casing and a, cavity 27in the slide valve 5, which cavity serves under release conditions as shown in the drawing to; establish communication between the. expansion chamber 25 and an atmos- 35 pheric port 28. z v

The operation of the apparatus is as follows: Under release conditions the triple valve piston and slide valveare in their left hand positions as shown :in the drawing in which the graduating valve 6 is closed ,and the brake cylinder is in communication with an atmospheric port 29 through" a recess 30 in the slide valve. Moreover the accelerating bulb or chamber '7 is in communication with the atmospheric port 11, as described which ,is in communication with the train pipe 24 is blanked by the slide valve 5; the diaphragm chamber'2l is'in:communication with the slide valve chamber 2 and the expansion chamber 25 with the atmospheric port 28.

Whenthe train pipe pressure is reduced in order to eiiectan application oflthe brakes, the triple valve piston 4 is :moved to the right, first lifting the graduating valve 6 from its seat and then shifting the slide valve 5 to its right hand or application position, the movement of the piston 4' and slide valve 5 being accelerated owing to communication being established between the port 31 in the slide valve seat which is in communication with the train pipe 24, and the port 9 in the slide valve seat. which is in communication with the bulb 7, this communication being established through the recess 10in the slide valve 5. In the right hand or application posi tion of the slide valve 5 the recess 27 in the slide valve establishes communication between the expansion chamber 25 and the diaphragm chamber 21'with the result that the diaphragm 18 is subject underneath to only a fraction of the auxiliary reservoir pressure, the value of this fraction being dependent upon therelative vol ,umes of the diaphragm and expansion chambers 21, 25. In the application position of the slide valve fluid under pressure is supplied from the auxiliary reservoir through the slide valve chamber 2and past the vunseated graduating valve 6 to the brake cylinder through a passage.32 in the casing 1 of the triple valve; The flow of fluid to the brake cylinder follows. two paths, the first traversing the calibrated orifice -14 in the plug cook 13 and-the second traversing the controlling valve 15 referred to hereinbefore and the calibrated orifice 17in the seat 16 of said valve.

Fluid is therefore supplied relatively rapidly to the brake cylinder so as to applythe'brake blocks,

downwardly and permits the controlling valve" 15 to seat. Thereafter fluid is supplied tothe' brake cylinder through the two calibrated orifices 14 and 17 only so as. graduallyto build up the r i a chamber in communication with the opposite side of said abutment, means for supplying'fluid braking pressure. 1

It will be evident that the invention is notlimited to the particular construction and arrangements of the parts hereinbefore described which .may ,be varied as desired to suit particular requirements without exceeding the scope .of-"the invention.

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

'1. A valve devicefor regulating the flow of fluid under .pressure to the brake cylinder of fluid pressure braking apparatuscomprising in combi nation a movable abutment subject on one side to the pressure in the brake cylinder, means for subjecting the opposite side of said abutment to a pressure which is substantially constant while the brakes are being applied and which is a predetermined fraction of the normal pressure in said braking apparatus, and a valve operated by said abutment for controlling the flow of fluid pressure in the brake cylinder, means for subjecting the opposite side of said abutment'during the release of the brakes, to the normal pressure obtaining in the apparatus, means for subjecting this side of the abutment to a substantially constant pressure which is a predetermined fraction of said normal pressure during the application of the brakes, and a valve operatedby said abutment for controlling the flow of fluid to the brake cylinder. 7 p r 3. A valve device for regulating the flow of fluid under pressure to the brake cylinder of fluid pressure braking apparatus comprising in combina- 5 tion a movable abutment subject on one sideto i subjecting this side'of said abutment to a different pressure from said normal pressure which is substantially constant during. the application of the brakes, and arvalve operated by said abutvment for controlling the flow of fluid to the brake cylinder.

4. The combination in fluidpressurebraking 7 apparatus of a distributing valve having a release I position and anapplication position, a regulating valve forcontrolling the supplyof fluid under pressure to the brake cylinder of the apparatus through said distributing valve, a movable abutment for operating said regulating valve and subject on one side to the pressure in said brake cylinder, means for supplying fluid .at one predetermined pressure to the opposite side of said abutment when the distributing valve is in its 2 release position and means for subjecting the opposite side of said abutment to a different pree j sof f determined fluid pressure which remains-sub stantially constant when said distributing valve is in its application position. i.

5. The combination in fluid pressure braking apparatus of a distributing valve having, a release position and an application position, a'regulating valve for controlling the" supply of fluid under pressure to the brake cylinder of the appa on,one side ,to the pressure in said brake cylinder;

at a predetermined pressure to said chamber when said distributing valve is in its release posi- 1 tion, a second chamber and means for cutting off" the supply of fluid to said first chamber and for establishing communication between said cham-1, H

bers when said distributing valve is in its application position to provide a substantially constant pressure less'than said predetermined pressure in the chamber in communication with said opposite side of the abutment. 1

6. The combination in fluid pressure braking apparatus of a distributing valve having a' release position and an application position, a' regulating valve for controlling the supply of fluid under pressure to the, brake cylinder of the v apparatus through said distributing valve, a movable abutment for operating said valve and subject on one side to the pressure in. said brake cylinder, a chamber in communication with the opposite side of said abutment, a second chamber,

' means for supplying fluid under pressure to said first chamber and for venting said second chamber when said distributing valve is in its release,

position and means for cutting off thesupplyi of fluid under pressure tosaid first chamber and for establishing communication betweensaid" chambers when said distributing valve is inv its applicationposition to provide in said first chamher a pressure which remains substantially constant while the brakes are applied.

THEOPHILE TARISIEN. I j i

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