US1113720A - Slack-adjuster for railway-brakes. - Google Patents

Description

APPLICATION FILED JULY 28,1913.

F. 11. WARD. SLACK ADJUSTER FOR RAILWAY BRAKES.

Patented 001$. 13, 1914.

Inventor:

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P. D. WARD.

SLACK ADJUSTER FOR RAILWAY BRAKES.

APPLICATION FILED JULY 28,1913.

1 1 1 3,720. Patented Oct. 13, 1914.

2 SHEETS-SHEET 2.

. a Attest: Q Inventor:

M m M To all whom it may concern more STATES Parana FRANK I). WARD, OF NEW YORK, N. Y., ASSIGNOR TO SAU'VAGE WABD BRAKE COMPANY, A CORPORATION, DELAWARE.

stac'mnmns'rnn Eon "RAILWAY-BRAKES.

Be it known that I, FRANK D. WARD, a citizen of the United States, residing in the borough of Manhattan of the city of New York, in the State of New' lork, have invented certain new and useful, Improvements in Slack-Adjusters for Railway-Brakes, of which the following is a specification, reference being bad to the accompanying drawings, forming a part hereof.

it. has been proposed to construct automatic slack'adjusters for railway brakes substantially of a slidable spring-pressed take-up rod and a rack bar movable in one direction only by-t he take-up rod upon the return of the latter to its normal position after excess travel thereof brought about by slack in the brake rigging, whereby the fulcrui'n of the brake system is shifted to compensate automatically for such' slack. In devices of this character it is necessary to provide adequate means for releasing entirely the. brake rigging in order that new shoes may be insertedor other usual repairs and adjustments made. In some instances it may be desirable to have theholding devices releasableby operation of the rack itself and by a simple manipulation necessitating the use of only one hand of the'repair man. i

It is the rincipal object of this invention to provide olding devices of the character above referred to and adapted to be employed' in connection with automatic slack adjusters of the general type above described which may be released by operation of the rack itself and by'a simple manipulation of one of the constituent parts of the slack adj listing devices proper. j A further object is to-improve slack adjusters of the rack-bar type generally by increasing their strength and incasing the moving parts more completely than has been possible hitherto. l

Other objects will. appear hereinafter as this description proceeds, reference now being had to the accompanying drawings for a detailed description of the invention. I In these drawings-Figure 1 is a fragmentary view in side elevation of a part of the wheels and truck of a railwa car equipped with the improved slack ad uster. Fig. 2 is a view on anenlarged scale, in side elevation, of the improved adjuster, part of the'casing being removedto show theopera- I specification of Letters Pas-1 Patented Oct. 13, 1914 Application filed July 2s,191a. Serial mi 781,489.

the parts of theadjuster which are shown .in the positions which they occupy"when the brake is applied, the take-up rod being retracted from its normal position of rest within the-casing. Fig. 3'is a view takenonthe plane indicated by the line 3 -3 of Fig; and looking in the direction of the arrows.

'lfig. 4 is a View, partly in section. taken on the lane indicated by the broken line 4--l of B lg. 2 and looking in the direction of the" arrowsg'therack-bar and brake system being shown in full release position. I In Fig.1 is illustrated in a somewhat'conventionalmanner somuch of a railway brake rigging as is necessary for a clear under standing of the application of the improved rack-bar slack adjuster. 'The brake shoes at, a are shown as suspended by links 11,. b from the cartruck (not illustrated) and con- ;trolledin their movement by a live lever o and'a dead lever d respectively, these open [ati ng levers being inter-connected adj acent f their lower-ends by the usual bottom rode. During the normal applicationof the brakes" the" upper. end of the dead lever d remainsrelatively stationary and constitutes a fnl-jcram about which swing the remaining .niovingpairts of the brake rigging. In the present" instance; the upper. end of the dead lever d is '1 connected through a suitable chain. (1' with a rack-bar (i horizontally disposed within a suitable casing which may be conveniently formed of two parts fund f rigidly secured together as by bolts f It will a )pear, how-- ever, asthis description proeee s, that the invention is not to be limited to the character of the casing employed for the moving parts of the slack adjuster but that casings of other forms than that herein illustrated will lend themselves to the practice of the present invention. The casing composed of the twoparts f and f, which-will be termed generally hereinafter the 'inclosing or supporting casing, ma besupported directly from the car body not'illustrated) by i a suitable'two-part clamp g'engaging trnnnionsf formed on the outer side walls of the sections f and f of the inclosingcasing and adjacent their ends. The other end of the inclosing casing may be pivotally se cured to the car body as through links h, thus permitting a slight movement of the supporting casing as mayfbe necessary to compensate for strains inoidental to the use of the devicea' I Iangle of approximately 90.

, sons which will hereinafter appear. However, the fornrof the rack-bar may be changed also without departing from the spirit of the-invention, except that it will be found desirable in practice to provide cylindrical bearing sections therefor in order that it may be rotated'readily in its supporting casing, as will be understood. The

rack-bar d has formed in it a series of teeth (Z3, the chords vof which subtend a central Cooperating with these teeth d to hold the rack-bar against movement in one direction is a dog 2' mounted pivotally Within a chamber 7 formed in the side wall of one of the sections 7' of the supporting casing. The dog isis normally held in engagement with the teeth (i of the rack-bar d by a suitable spiral spring 7' operatively disposed within the chamber f. It will now-appear that so long as the dog 2' is in engagement with the teeth (Z of the rack-bar d movement of the upper end of the dead lever d to the right,

I as viewed in Fig. 1, cannot occur.

The sections, f and f constituting the inclosing casing for the sliding rack-bar d are formed to receive also a sliding take-up rod is operatively connected through a chain Z2- with the upper end of the live lever 0 and the usual pull rod Z, the latter being connected to a suitable source of power. The inner end'of the take-up rod is may be partially supported and guided in its movement by a pin 70 the ends of which are disposed within suitable longitudinal grooves formed in the opposite side walls of the sections 7"" and f of theisupporting casing. Pivota'lly mounted on the pin if within the casing constituted by the sections f and f is a pawl m, the toe of which normally cooperates with the teeth d of a second rack formed on the rack-bar d asv shown'most clearly in Fig. 4. The chords of the teeth d" may, also snbtend substantially a central angle of 90 on the rack-bar 6?, so about one-half, more or less, of the surface of the rack-bar d is taken up by the two racks formed by the teeth (Z and d, the rest of the surface. of the rack-bar being truly arcua'te in outline. In addition to the supporting pin, of the pawl m a second stud m maybe formed integral with or secured to the pawl and have its end resting somewhat loosely in guide grooves or shoulders 7 also formed in theinner side walls of the sections f and f of the supporting casing. The inner-ends of the grooves or shoulders f are inclined, as at f, as shown best in Fig. 2, so that when the take-up rod k is forced leftwardly, as ..viewed in this figure, to its :extreme position the stud m, following the inclination f of the guide grooves f, serves to retract the pawl m from its engagement with the teeth (Z of the rack-bar (1. This movement of the take-up rod l: and the pawl m, when the brakes are released, is brought about by a suitable spiral spring a disposed within the casing constituted by the sections f and f and interposed operatively between one end wall of the casing and the pawl m.

When the brake shoes are adjusted properly and there is no slack in the brake system, the pawl m is held outof engagement with the teeth at of the rack-bar d by reason of the position of the stud m on the inclined portion 7" of the guide shoulders f". The holding dog i is at this time in engagement with one of the teeth d of the other rack on the rack-bar (P. It, now, the brakes be applied by application of power through the pull rod 1 the upper end of the dead lever (I will be held relatively stationary by reason of: the engagement of the holding dog '5 with the teeth (Z of the rack-bar (1 while the take-up rod X: will be drawn to the equal to the normal travel of the pull rod l,

as measured in linear units, so that, normally, at the instant the brakes are completely applied the stud m will rest on the lower section of the inclined portion f and the toe of the pawl m will be almost in engagement with the teeth d of the rack-bar When the brakes are released the spring 12- will force the take-up rod together with the pawl '/n to the left, as viewed in Fig. .2, so that the stud m, will again ride up on the inclined portion f and the pawl be returned to its normal resting position. During this operation the spring a serves as a release spring to move the brakes to their release position. Of course, at this time the rack-bar (Z maintains its fixed position. If, on subsequent applications of the brakes, slack occurs in the brake system, the takeup rod it will have an excess travel equal to the amount of slack within the brake rigging so that the stud 712/ will more oil of the inclined portion f of the guide shoulders f and the toe of the pawl on will come in engagement with the teeth at of the rackbar (Z Perhaps this excess travel will be sullicient only to more the toe of the pawl m over one of the teeth oi the rack-bur or perhaps this excess travel may cause the toe to move over two or more teeth. At all events when the brakes are again released the engagement of the pawl m with one of the teeth d of the rack-bar (1 will result in the rack-bar (Z being moved to the left, as viewed in Fig. 2, under the action of the spiralspring it, until the stud m again restson the inclined portion f of the guide shoulders 7' and so retracts-the toe of the pawl from engagement with the teeth 03. After shifting; the rack-bar d to an extent qual tothe excess travel. of the take up rod '/v, in the manu'er 'pomted out, thetake-up rod. continues i'ts movement to the left, as

viewed in l l'gi: 2,-u distance equal toits normail trave'L The operation of the parts above referred to is the same in some respects as that found in some other constructions nowv known.

\Vith the description thus far given,'however, the gist of the present'invention can now understood more readily; It will be observed that the free end of the rackc'loar-cl is provided with a depending handle r1 If this handle be grasped by the repa1r .man and swung in the direction of the arrow indicated in Fig. 4%, the rack-barwill be ro-' 'tated so that-the teeth (Z will be moved out of engagement with the holding dog v1 and the toe'o f the latter will rest on the cylin- 1 dr'ical-portion of-t'he rack-bar, as shown in full lines in Fig. 4. It will'be understood that the rack-bar d will now 'be free to slide in the direction of releasewithin the inclosing casing so that the brake rigging may be released completely and newbrake shoes inserted or other adjustments or repairs made readily.

From the description given it will be evident that a repair man by a simple'manipulation requiring the use of one hand only may release the rack-barfrom engagement with the cooperating parts of the slack adjuster and simultaneously move thesame to a position where the brake rigging will be released completely. The handle returns to proper position for action by gravity, and the holding dog 2' resumes its engagement with the teeth (l The repair man Willthen make'the necessary repairs l'eavingthe adjustment to be done by the device automatically. The next following application and release of the brakes will serve to move the rack-bar to :1 position where the upper end of the dead lever will constitute a proper fulcrum for the brake rigging and insure the normal travel of the pull rod.-

lllodifications in the details ofconstruction and arrangement of parts may be made without departing from the spirit of the present invention, provided such modifications and rearrangements fall within the scope of the appended claims.

I claim as myflinvention:

1. The combination of a car body, a truck.

a brake system comprising a live lever and a dead lever, and an automatic take-up do vicemounted on the car body and com'pris- I 'ing two rodsoperatively connected to the (lead lever and to the pull rod respectively and relativelystationary hold ng means cngaging the first named of said rods to prcvent positively movement thereof in one di-- rection-y while permittin free movement thereof in the opposite c irection, said first named rodv being rotatable to be released from the holding means and therefore free to-be moved bodily in an axial direction. to

permit the brakes to be swung from the wheels.

2 The combination of' a car body, a

truck, a brake system comprising alive 1everan'd adead lever, and an automatic takeupdevice mounted on the car body and com-'- prising a rack-bar operatively connected to the dead lover, a 'reciproo'able take-up rod operatively connected to the live lever, relatively stationary holding meansto' pre vent travel of the rack-bar in one direction, said means permitting free movement thereof in the opposite direction, the take-up rocl being operative after excess travelto shift the (rack-bar, and the rack-bar being rotatable to be released from the holding means and therefore free tobe moved bodily inan axial direction to permit the brakes to be swung from the wheels.

3. The combination of a car body, a truck, a brake system comprising a live lever and a dead lever. and an automatic take-up device mountedon the car body and compris- ,1

ing two rods operativelyconnected to the dead lever and to the pull rod respectively,

.a stationary,spring-pressed holding ,dog in engagement with the first named rod and a pawl operatively connecting the two rods, the first-named rod beingrotatable to be re leased from the dog and the pawl and therefore free to be movedbodily in'a-n axialdirection to permit the brakes to. be swung from the wheels.

4; The combination of a car body, a truck. a brake system comprising a live lever and. a dead lever, an automatic take-up device in eluding supporting means mounted on the car body and comprising a rack-bar and a take-up rod, both slidably mounted in said supporting means, said rack bar being provided with two series of teeth, a pawl carried by the take-up rod, a shoulder being formed on the supporting means and co opcrating with the pawl to hold the same out of engagement with the teeth of the rack during normal travel of the pull rod and permitting engagement of the pawl with one series of teeth of the rack upon excess travel of the pull rod, a spring pressed holding dog carried by the supporting means and in engagement with the other series of teeth on the rack-bar, and means to return the pawl to normal position upon the release of the brakes.

' vided with two series of teeth,

The combination of a car body, a truck, a brake system comprising a live lever and a dead lever, an automatic take-up device including supporting means mounted on the car body and comprisin a rack-bar and a take-up rod, both slidab y mounted in said supporting means, said rack-bar being proa pawl carried by the take-up rod, a shoulder being Jforin'ed on the supporting means and cooperating with the pawl to hold the same out of engagement with the teeth of the rack during normal travel of the pull rod and permitting engagement of the pawl with one series of teeth of the rack' upon excess travel of the'pull rod, a spring-pressed holding dog carried by the supporting means and in engagement with the teeth on the rack-bar, and means to return the pawl to normal position upon release of the brakes, said rack-bar being rotatable to disengage the respective the pawl and the dog.

The combination of a car body, a truck, a brake system comprising a live lever and a dead lever, an automatic take-up device inoluclin supporting means mounted on the series of teeth from car body andcomprising a round rack-bar and a take-up rod, bot-h slidably mounted in said supportmg means, two series of teeth formed on thepe'riphery of said rack-bar other series of a brake system comprising a live lever and a dead lover, a two-part casing supported on the car body, an automatic talie-up device supported in said casing and including two rods oporativoly connected to the dead lever and to the pull rod respectively, a chamber formed in the side wall of one of the sections'of said casing, a spring-pressed holding dog mounted in the chamber and adapted to engage the first named rod, a pawl supported within said casing on the inner end of the second named rod and operative upon excess travel of the pull rod to connect said two first named rods, and guide shoulders formed on the inner side walls of the sections of the casing and cotiperating with said the same.

8. The combination of a car body, a truck, a brake system comprising a live lever and a dead lever, a two-part casing supported on the car body, an automatic take-up device supported in said casing and including two rods operatively connected to the dead lever and to the pull rod respectively, a chamber formed in the side wall of one of the sections of said casing, a spring-pressed holding dog mounted in the chamber and adapted to engage the first named rod, a pawl supported within said casing 011 the inner end of the second named rod and operative upon excess travel of the pull rod to connect said two first named rods, and guide shoulders formed on the inner side walls of the sections of the casing and cooperating with said pawl to determine the position of the same, the first named rod being rotatable to release it from the dog and the pawl.

This specification signed and witnessed this 24th day of July A. D. 1913.

FRANK D. WARD. Signed in the presence of E. M. TAYLOR,

lVon'rmno'roN CAMPBELL.

pawl to determine the position of

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