US2514588A - Railway car brake and slack take-up system - Google Patents

Description

July 11, 1950 K. F. NYSTROM El'AL RAILWAY CAR BRAKE AND SLACK TAKE-UP SYSTEM Filed April 29, 1946 4 Sheets-Sheet 1 INVENTORS [lg 5Z3 [Karl F Vernon L. Green y 1950 K. F. NYSTROM ETAL 2,

RAILWAY CAR BRAKE AND SLACK TAKEUP SYSTEM 4 SheetsSheet 2 Filed April 29, 1946 INVEN TOR. gym? [Jazzl E Grsen I/grnozz hwy y 1950 K. F. NYSTROM ETAL 2,514,588

RAILWAY'CAR BRAKE AND SLACK TAKE-UP SYSTEM Filed April 29, 1946 4 Sheets-Sheet 3 INVENTOR. ECZlfl f N .sirom gernozz .Greezz any July 11, 1950 K. F. NYSTROM ET AL RAILWAY CAR BRAKE AND SLACK TAKE-UP SYSTEM 4 Sheets-Sheet 4 Filed April 29, 1946 INVETOR. E6032 I'T'Ngsram lferzzolz L. Greenany Patented July 11, .1950

nmwhnokiwmnannn sm'ox TAKE-UP SYSTEM.

i-vemnnereen; Milwaukee; Wig;

i lpplicationtApriLfi, 1946 zs riarnnessaszt coinin (c1. rap-2cm v Our invention relates to brake systems ofgthe hydro-pneumatic type, more" especially'ilntended for railway passenger cars,.and contemplating fthe direct application oiLth'e actuating cylinders to the brake heads. v

The invention has for one of Iits"objects;.a"brake system wherein the brake meanseshoesf'and hangers-are alli mounted between the truck wheels,,thereby eliminating'the'ineedforany'out board brake shoes" and all the auxili'aryappuw tenances necessaryior their attachment and application. U

Another obj ectof our inventionis the;provision of a: construction and" arrangement 'WhEIilIf'thB overturn moment on the tmoiifiamet duelto'rthe hanger forces during brake" application will. be greatly reduced;

A further object? entire-invention istherprovision of a construction wherein "smaller sizedactm ating cylindersmay be employed; 'the' number of pins, levers, brake beamsand pull rods materially reduced; andl'hence a construction and arrangement' of less weightprovided-a 'desideraturn in high'speedoperation; I

Our invention also contemplates"thezprovlsion Of automatic slack controlmechanism whereby the degree of return movement "of the actuating cylinder; its piston and associated brakeswill 'be automatically controlled or'limitedftocompensate for small diameter. wheels .and7or' :greatly'Wom brake shoes.

The aforementioned objects" and :advantage'sas; weilas other'advantagesinherent mom-improved brake system will all be readily-comprehended from the detailed description of the accon'ipanying'drawi'ngs, wherein:

Figure l is 'a perspective"andmore'or"lesssche matic view of a railways car truck (with portions which form" no 'part' of the present invention broken away) showing: application-of our firmproved brake construction.

Figure '2'is a perspective view'ofthe"powerccyl inder, with portions broken away and in section to show internal'construction.

Figure 3*is asimilar View of one of theactuat ing cylinders shown iii-longitudinal section:

Figure 4' is =a-- detail side elevationof 'the piston rod end of the actuating *cylinder as yiewedirom the near side 'in.Figure 3; with. the: piston rod omitted.

Figure 5' is a 'sectional' view taken on=thez=oifse line 5-5'infFigure14i Figure 6 is a horizontal sectional'view taken on the lineB-G of'Figure-ifi;

Figure"? isa detailsectionai the line 'I-Ibtflgurefip The parti'cular exempl" cation of ourimproved hydro-pneumatic brake system and arrangement shows its applicationitora, railway passengercar' truck schematically"illustrateddn Figure 1 with portions" of the (side frame members broken-away and"pro'vided withi'the usual Wheels l5 andthe brakehead's l 6 mounted between'thewheels- The brake heads lfia'reprovided with standard brake shoes l'l'. 'I'he'brak'e heads I Gare pivotalliy carrie'dbiy thecombinationbrake' levers and hangers I 8 offproper'anfgular ftorma'tion; whose upperends arependently supported" by'the transomimembe'rs IBiotfthetruckimmd The air br'a'ke" line: control m'ay beioif the con"- venti'onaltype but instead oftheair entering-the brake cylinder; it igconveyedby the'line' or hose 2!! tothe' power 'cylinderlfi, disposed transversely of the'truc k and suitably secured to the'truc'k frame against movement}: the" line or" air hose 2'0 beingsuitably secured to the side of thecylin'der 2 I at a predeterminedfpointintermediate the ends ofth'e cylinder; as more ciea'rlyishown inFigure'Z.

"The endsofthe' cylinder shell are closedby similar chambered- closure members 22, 22; removablysecured 'in' place ibythe rods 23; the closure' 'members" 22 being e'a'ch providedwith' a fluid chamber or reservoir 25 surroundingjaoen' tral auxiliarycylihder portion 25 the reservoir apluggeddrain opening at'2'6i 'Tl'ie'oylinder -z liis' provided"withapair' of sinu m pistons" with beveled heads arranged :at oppo' site "sidesof? the: airin'let' of hose "2!!" thebevel'ed h'eadsprovlding annular" aircha'mberbetween the pistons; one "piston being shown" at 21, pro vided with "a'suit'able "packing element 28: The piston'is-secured-to the piston rod 29 whose opposite en'dextends through the packing gland 3i! and the end" ofthe ro'd provided with suitable hydraulicpacling at 3 I *to" eifect'fiuidtightsliding relation with" the auxiliei-ry cylinder 25'; which latter ati'a' predetermined point is provided with aport32 for replenishing the cylindricalchamber 25 with hydraulic fluid fromthe-surroundingreservoiror chamber 'H duringpi'ston or brake operations. An auxiliary port f 24 is provided to prevent oil being 'trapped between: replenishing port 32'and gland' '30 The piston rod 29 is surroundedwitli a suitable return or coil spring' 33, seated a'gainst the closure member 22 and' the piston 2 T for returning. the latter to its normal position when adinissibn "of air'through-hose 20 is shutoif;

Horizontally disposed" between the lower ends of the combination:brakelevers and hangers l 8; l8"; namely beneath the pivotar-connections' of said levers and hangers with the brake heads, is an actuating cylinder 34 of comparatively small size, preferabl five inches, whose head end is provided with a pipe or preferably flexible hose 35 communicating with the cylinder interior, while the other end of this hose 35 is connected with theloutlet, plugpr nipple .2 ,o the .aizl xiliary in rt qn z lo lih w r c l n e a similar connection being made at the opposite end of power cylinder 2| and the actuating cylinder 34--not shown-at the opposite side of the truck) '1 The head of actuating cylinder 34 is provided with a clevis or pair of apertured lugs 3G whe'reby the cylinder 34 is pivotally secured to the; lower end of one of the combination brake levers and hangers l8. The cylinder 34 is provided rate with the authorized or required brake shoe movement' from braking position to release positio'n;-we provide the inner perimeter of pinion 45 with anarcuate slot or key-way 52 (see (Figure with a suitable piston 31, provided'with suitable" hydraulic packing 38 and secured to theinner;

end of the piston rod 39 which extends through the other end of thecylinder and through a suitable closure member and guide sleeve portion 40, s ee'Fi'gure 3. i I

The piston rod. 39 within, thecylinder 34 is surrounded by avsuitable'spring 4| wher'ebythe cylinder and piston are returned to normal 'posie tion when the pressure on the introduced hy-f draulic medium is no longer existent. The outer end of the piston rod or stem 39 is by the piston'stem 39 is pivotally connected to the lower end of the other combination brake lever and hanger member l8. As is apparent, the

actuating cylinder 34 with its piston is pivotally provided with a clevis or bifurcated end 42 whereg supported and carried'by the lower ends of the two combination brake levers and hangers, so that any relative longitudinal movement between cylinder 34 and piston stem 39 will induce oscillation of the two brake levers and hangers and cause brake head and shoe movement toward and away from the respective or adjacent truck wheels, as the oil or hydraulic medium under pressure entering .the actuating cylinder 34 above or at the upper side of the piston 31 will exert ment of both.

' As the quantity of oil or hudraulic medium discharged from the inner cylinder or chamber 25' of the power cylinder ismore or less limited, it'is essential to provide means whereby the return movement of the actuating cylinder and its piston will be limited so as to obviate the necessity for the actuating cylinder andits piston to make a complete distending stroke duringbrake application in other words that sufiicient pressure on-the brake heads and shoes may be obtained to effectproper braking conditions Therefore, theguide sleeve portion 40 of the actuating cylinder 34 ,is shown provided with a transversely disposed shaft 43 provided with a pairvof spaced apart pinions 44 and 45 (see Figure 3), the pinion 45 meshing with a rack46 arranged lengthwise of the piston rod 39.

-' l Secured to theinnerend of aloosely mounted pin 41 is a pawl48 which is held in operative relation c with pinion 44 by :a suitable spring .49

-'its"pressure against the cylinder'head or end as well as on the piston thereby cause outward move- 6). of predetermined length or degrees corresponding to the degree of shoe movement to release'positioni'adapted to receive a Woodruff key 53;;the outer end of shaft 43 being shown squared or given angular cross-sectional configuration to receive a suitable hand-crank whereby proper manipulation of the slack, take-up mechanism may be had duringinitialinstallation and adjustmentjo f the mechanism in keeping with brake-shoeand wheel cor'iclitions'. l

The non-pressure cylinder head or piston rod guidesleeve 40 is held in its proper screwed on position on the cylinder 34 by a -locking ring 54; while the guide sleeve 40 is provided with a grease filler opening having a plug as at 55; and the end of the -guide 1 sleeve preferably is provided with a guide bushing 56, having a grease and dirt-seal5'l, v The reservoirs 2'4 and inner chambers or cylinders' 25 at both enas'or the power cylinder 2| are initially [filled with oil or other suitable hydraulic medium which permits a portion of the medium tofiow through thepipeor hose connections 35 toward the pressurehead ends of the respective actuatingcylinders 34atopposite sides of the Upon admissioniof the compressed air, from the usualcompress'ed air supply of the train, into power cylinder 21 by the "connection or hose 20, the two pistonszl will be ,forced'toward the ends of the cylinder 2 l""against the action of springs 33,- Such movement .of vthe piston 2'! will'cause the small piston and its packing 3,! to close the replenish vport.342,!therebyfplaicin the oil or hydrauliclvfluid vin inner cylinder or chamber 25 under pressure and forcing it into'the pressure head endof the actuating cylinder 34' and inducing extending movement between the cylinder 34-and. its pistor'i 3'lfaigainst the action of the spring 4 I Such-Q extending or' outward move ments of the cylinder and piston will oscillate the combination brake levers and hangers l8, l8 and move the brake heads and associated shoes into brakingposition. This'feo'ndition will maintain as longas compressed-air is admitted to the power cylinder. Duririghsuch outward movementof the actuating m nd r, and its piston 31, the Woodrufikey 53 will beat the left hand end of the keyway orsarcuate slot 52 as shown in Figured ns-soon as pressure on the hydraulic ;,1 luid z-ceases; spring ,4! will move the cylinder. 34-. and piston 31 ,toward 4 contracted or normal position, causing' the piston rod rack 46 to revolve control gear .017 pinion 45 (which is free to rotate on shaft 43) a degree corresponding with the width or;.;length of the arcuate slot or keyway 52 until the key 53: engages the other or ri h ha d: end o h -ke way 5 thereby efiecting operative relationbetween pinion-45' and h sha t, 35 i lurthereba kw d ro o he slack control gear or rack engaging pinion 45- will be prevented by the pawl "4'8 and'pinion-44 which is immovably secured on the shaft 43 to which the Woodruif key 53 is secured; the length of the slot or keywayiZ .being predetermined to provide the prescribed clearance between shoe and wheel while in brake released position. With the limited quantity of hydraulic fluid or volume of oil carried by the power cylinder it .is not feasible to require the actuating cylinder and its piston to travel a full stroke. In order to provide a properly workablestructure it isnecessary to provide the means described whereby a complete return stroke of the actuating cylinder and piston will be prevented.

When the flow of compressed air into power cylinder 2| is shut off, the combined pneumatic piston and hydraulic piston will return to normal position, through the actionof spring 33, thereby uncovering thereplenishing port .32 and permitflow of the fluid from the reservoir 24 into inner cylinder '25 and fill the latter which is of comparatively small diameter. The actuating cylinder and associated piston having previously been/extended or adjusted in keeping with wheel diameter and brake shoe condition, the power cylinder during the next brake application need furnish only enough oil or hydraulic fluid to ex-' tend-or move the actuating cylinder and piston a comparatively small degree corresponding with the amount of brake release movement permitted during the preceding brake application and controlled by the length of the slot or key-way in the freely mounted pinion 45, provided the brake shoes have not become, worn during the preceding brake'application.

In the event wear has occured, the actuating cylinder and its associated piston will be extended or movedoutwardly, upon the next brake application, av distance corresponding with the amount .of brake release plus the brake shoe wear and thus cause the key 53 to rotate slack control shaft 43 andpinion 44, in clockwise direction as viewed in Figure 3, and permit the pawl to, engage the succeeding tooth or teeth as thecase may be, thereby holding the piston rod against return movement beyond that permitted by the slot-and-key connection between rack pinion 45 and slack control shaft 43.

As is apparent, this operation will take place and be repeated as brake shoe wear increases during subsequent brake applications and the brake shoe wear is sufiicient to enable the ratchet pawl to engage the next tooth of ratchet pinion 44. In the event the wear is of a degree less than the width of the pinion tooth, the ratchet pinion will turn backward until the spring pressed pawl engages the original tooth.

By providing the pawl carrying pin or shaft 41 with the release lever 5|, the car inspector may release the pawl 4'8 from the ratchet pinion 44 thereby permitting the actuating cylinder and associated piston, through the action of the spring '4 l, to return to complete contracted condition and provide ample clearance for removal and application of the brake shoe.

The initial adjustment of the actuating cylinder and associated piston is made by the air brake man in keeping with regulations which require him to make a number of brake set and release operations and tests before the car leaves the terminal; during which testshe must see that every brake shoe properly contacts the wheels. I

The closure members 22 at the ends of the power cylinder 2| are each shown provided with a filler and breather cap as :at58, seeFigure-2, whereby the oil or hydraulic fluid may be introduced into the inner cylinders 25 and reservoirs 24 and the desired quantity maintained.

The exemplification shown in the drawings is believed to be the simplest adaptation of our invention, but modifications are possibleand may be made without, however, departing from the spirit of our invention as defined in the appended claims.

What we claim is:

1'. In a railway car brake and slack take-up system involving a source of hydraulic pressure fluid and pendently supported brake heads; brakeactuating means comprising a pressure fluid receiving cylinder connected with said source and having a reciprocable piston provided with' an elongated stem extending through one end of' the cylinder, one end of the cylinder having operative pivotal connection with one of said brake heads while the end of the piston stem has operative pivotal connection with the other brake head; automatic means whereby the cylinder and pistonare forced towardnormal contracted condition; a rotatable shaft arranged adjacentzsaid piston stem; ratchet mechanism operatively' connected with said shaft for holding the latter against reverse rotation; rack and pinion connection between said shaft and said piston stem whereby said shaft rotates forwardly when said piston stem moves outwardly; and means operatively intermediate said pinion and said shaft whereby the pinion and piston stem are per mitted a predetermined degree of reverse movement corresponding to the prescribed brake head release movement.

2. In a railway car brake and slack take-up system involving a source of hydraulic pressure fluid and pendently supported brake iheads;

brake actuating means comprising a pressure fluid receiving cylinder connected with said source and having a reeiprocable piston, one end of said cylinder having operative pivotal connection with one of said brake heads while the'outer end of the piston stem has operative pivotal connection with the other brake head; means whereby the cylinder and piston are forced toward normal contracted condition; a rotatable shaft disposed transversely of said piston stem; ratchet mechanism for holding said shaft against reverse movement; and mechanism operatively associated with said piston stem and with said shaft whereby the latter is forwardly rotated during outward movement of the piston stem and said piston stem permitted a predetermined degree of reverse movement corresponding to the prescribed brake head release movement.

3. In a railway car brake and slack take-up system involving a source of hydraulic pressure fiuid and pendently supported brake heads; brake actuating means comprising a pressure fluid receiving cylinder connected with said source and having a spring controlled reciprocable piston provided with an elongated stem extending through one end of the cylinder, one end of the cylinder having operative connection with one of said brake heads while the outer end of the piston stern has operative connection with the other brake head; a rotatable shaft disposed transversely of said piston stem; a pinion fixedly secured to said shaft to rotate therewith; a pawl arranged in tooth engaging relation with said pinion to hold the latter and said shaft against reverse rotation; a rack and pinion connection between said shaft and the piston stem whereby forward rotation of'said shaft is obtained when the piston stem moves outwardly; and means operatively intermediate said last mentioned pinion and said shaft whereby the shaft and pinion are made to rotate in a forward direction but the pinion and said rack and associated piston stem permitted predetermined limited reverse movement corresponding with the prescribed brake head release movement. I i

4. In a railway car brake and slack take-up system involving a source of hydraulic pressure fluid and a pair of pendently supported brake heads; brake actuating means comprising a pressure fluid receiving cylinder whose pressure head end is connected with said source and having a spring controlled reciprocable piston provided with an elongated stem extending through the other end of said cylinder, the pressure head end of the cylinder having operative pivotal connection with one of said brake heads while the outer end of the piston stem has operative pivotal connection with the other brake head, said piston stem being provided with a lengthwisely disposed rack intermediate its ends; a rotatable shaft disposed transversely of said piston stem; a pinion arranged on said shaft and in mesh with said rack, the pinion being provided with an arcuate slot or keyway of predetermined length correlated with the prescribed degree of movement of the brakes to release position; a key carried by said shaft to extend into said keyway and of width less than the length of the keyway whereby said shaft is rotated by the outward movement of said piston when the key is at the rear end of said keyway; a ratchet pinion keyed to said shaft; a spring controlled pivoted pawl meshing with said ratchet pinion to hold the latter and said shaft against return or rearward rotation; and a release lever operatively connected with said pawl.

5. In a railway car brake and slack take-up system involving a source of hydraulic pressure fluid and a pair of pendently supported brake heads disposed between the wheels on the same side of the truck; brake actuating means comprising a pressure fluid receiving'cylinder connected with said source of pressure fluid and pendently disposed longitudinally between the wheels and operatively connected at one end with a brake-head While the other end of the cylinder is provided with an elongated guide sleeve; 2. spring controlled piston in said cylinder provided with a stem disposed through said guide sleeve with its outer end operatively connected with the other brake head, the portion of the piston stem within said guide sleeve being provided with a rack; a transversely arranged shaft in the guide sleeve provided with a pinion arranged in mesh with said rack, with the pinion having slot-andkey connection with said shaft, whereby a predetermined reverse movement of the pinion and the piston is permitted to provide for brake shoe release; pawl and ratchet mechanism in said guide sleeve operatively associated with said shaft whereby return of the cylinder and piston to initial contracted condition is prevented; and means whereby the pawl and ratchet mechanism may be released.

KARL F. NYSTROM.

VERNON L. GREEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 214,212 Waite et a1. Apr. 8, 1879 556,011 Macbeth Mar. 10, 1896 754,246 Scott Mar. 8, 1904 996,284 Schenck June 27, 1911 1,479,700 Djurson Jan. '1, 1924 2,238,452 Shafer Apr. 15, 1941 2,273,635 r Frede Feb. 17, 1942 2,382,444 .Rockwell Aug. 14, 1945 2,395,223 Ingres Feb. 19, 1946 FOREIGN PATENTS Number Country Date 411,567 I Great Britain June 14, 1934

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