US2263244A - Railway braking apparatus - Google Patents

Description

1941- V K. J. J. M GcwAN ETAL I 2,263,244 RAILWAY BRAKING APPARATUS Filed July 30, 1940 2 Sheets-Sheet l INVENTORS J1 eiawanmzd HQ PL.flane.

may: A'IFTORNE/Y Patented Nov. 18, 1 941 a Kenneth J. J. McGowan, Pittsburgh, and Herbert L. Bone, Forest Hills, Pa., .assignors to The Union Switch & Signal Company, Swissvale, Pa., a. corporation'of Pennsylvania Application July 30, 1940,- seal No.34s,592

6 Claims. ((1188-62) Our invention relatesto railway braking apparatus, and particularly to that class of braking apparatus known. as inert car retarders.

More particularly, our present invention relates to inert car retarders of the type described and. claimed in Letters Patent of the United States No. 2,104,606, granted to Herbert L. Bone on January 4, 1 938, for Railway braking apparatus. In the said car retarders, the braking barsare supported for swinging movement toward andaway froma track rail by means of levers pivotally mounted at their lower-ends on the base flange of the track rail by means of recesses which receive the base flange. The levers are biased toward the rail to their braking positionsby means of spring assemblies each of which includesa spring bolt extending through aligned clearance holes providedin the levers and in the rail web and a spring disposed on this spring bolt, and means in addition to the spring assemblies are provided to hold the lower ends of the levers in engagement with the rail flange when no car is in the retarder.

One object of our present invention is to simplifythe construction, and thereby decrease the cost of manufacture and maintenance, of car retarders of the type disclosed in the said Bone patent. V

According to our invention, we accomplish this objectby so constructing the spring assemblies that they not only serve to bias the levers to their braking positions, but also serve to exert on the associated leverwhen no car is in the 'retarder', a mechanical couple the effect of which is to hold the lever in proper engagement with the rail flange or other support without the necessityfor the other means which have heretofore been provided for this purpose.

Other objects and characteristic features of our invention will become apparent as the description proceeds.

We shall describe two forms of car retarders embodying our invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a verticalsectional view 'showingone form of inert car retarder embodying our invention. Fig. 2 is a side view of the retarder shown in Fig. 1 as it appears when viewed from the right in Fig. 1. Figs; 3 and 4 are views similar to Figs. 1 and-2 showing a modified form of the retarder illustrated in Fig. 1.

Similar reference characters refer to similar parts in each of the several views.

.characterl designates one track-rail of a stretch ,of railway track over which the wheels of cars which are to be retarded by the retarder are adaptedto pass, one such ,wheel 2 being shown in dot and dash lines in the drawings.

- The rail I is supported at spaced points on rail supports 3, and associated with each rail support is a spring unit U which serves as a means for biasing a braking bar B, which extends parallel to the rail, to a braking position in whichit will frictionally engage the Wheels of cars traversing the rail l. The braking bar B comprises, as usual, a brake beam 4 and abrake shoe 5.

l The spring unit U in the particular form illustrated comprises a vertically extending cast lever 6 disposed at the outer sideof the rail l, and

provided at its lower end with a rounded bearing surface Sawhich restson the base flange 3a of the support 3 between upstanding pairs of laterallyspaced lugs 1 and 8. As will appear presently, the lever 6 is intended to swing toward and away from the rail I about the bearing surface Ba as a fulcrum, and the lugs 1 and 8 cooperate With the opposite sides of the lever to loosely limit the distance through which the lower end of the lever is free to move laterally toward or away from the rail I. Excessive vertical displacement of'the lever 6- is prevented by a lug 3b which is cast on the support 3, and

. :which extends loosely into, and cooperates with,

, Referring first to Figs. 1 and 2, the reference 55 the lower end of a rectangular opening 61: which 2 is formed. in the lever intermediate its ends. The lug 312 also assists in positioning the lever longitudinally relative to the rail. This method of pivotallysupporting the lever B eliminates the necessity .for any extensive machining operations, and enables the cost of the retarder to be reduced to a minimum.

The opening 67) aligns at its upper end with an opening I 0 provided in the web of the rail l, and a vertical slot 30 provided in an upstanding arm 3d formed on the support 3 on the side of the rail opposite tothe lever 6. The slot 30 and openings l0 and 6b loosely receive a T-headed spring bolt 9, the head 9b of which fits between laterally spaced ribs 3e formed on the arm 3d in such manner that the bolt is prevented from rotating about its axis. The bolt, however, is intended to rock in a vertical plane a slight amount about the region of contact between the headQa andthe arm 3d on opposite sides of the slot3c, and to this end the forward faces of the two ends of the head are rounded in the manner shown.

the opening 6?) with horizontally aligned grooves 6d, which grooves receive the bulges Ha. The inside spring seat is also provided on the side opposite to the bulges Ha with a circular boss llb which serves to center the inner end of the spring relative to the bolt.

The outer spring seat I3 is provided with a laterally projecting skirt portion 13a. which cooperates with the spring l2 at its outer end to hold it in a centered position relative to the spring bolt 9, with two diametrically opposite apertured lugs I31) and [30, and with a. boss 13d. Two bolts I5 and I6 extend with some clearance through the apertures in the lugs I30 and I30, and through openings 6e and 6] formed in the lever 6 on opposite sides of the spring bolt 9 and are provided at their inner ends with nuts I! which fit in recesses 67; formed in the inner face of the lever. The bolts and I6 and nuts I! constitute a means for providing the spring l2 with an initial compression for a purpose which will appear presently, and the recesses which receive the nuts I! serve to prevent rotation of the nuts, whereby the desired initial compression of the spring 12 may be obtained by rotating the bolts by means of their heads since the bolt heads are more accessible than the nuts. After the desired initial compression of the spring [2 has been obtained, the parts are locked in their adjusted positions by a wire 24 threaded through holes in the heads of the bolts, and formed into a loop which surrounds the boss 301 of the spring seat l3.

The boss I312 on the spring seat I3 is provided on opposite sides of the spring bolt 9 with rounded bulges I3e which cooperate With rounded recesses I la provided on the inner face of the nut I l to automatically lock the nut against unwanted rotation.

The lever 6 is further provided with an L- shaped upper surface 6g which supports the brake beam 4, and with a horizontal shoulder 67' which partly supports the brake shoes 5 of the braking bar. The brake beam 4 is secured to the lever by means of two vertical bolts 23 which extend downwardly through longitudinally spaced clearance holes in the brake beam and aligned holes in the lever, and which are provided at their lower ends with lock washers l8 and nuts l9, while the brake shoe 5 is secured to the lever by means of a pair of horizontally disposed bolts 29 which extend through aligned holes in the brake shoe and in the lever and are provided at the outer side of the lever with lock washers 2i and nuts 22.

The parts are so proportioned that lever B is biased by gravity to swing in a clockwise direction, as viewed in Fig. l, but that this biasing force is insufficient to compress the spring [2 beyond its initial compression. It will be apparent, therefore, that when no car is traversing the track rail within the limits of the car retarder, the spring bolt 9 will be held in the position in which its head 9a engages the arm M on the rail support 3, and the lever B will be biased toward the rail by the spring 12 to a position which depends upon the adjustment of the nut M. The nut 14 will usually be so adjusted that when no car is passing through the retarder, the lever B will occupy a position in which the brake shoe 5 projects into the path of car wheels traversing the rail 1, and it will be seen, therefore, that when a car enters the retarder, the wheels will engage the brake shoe 5 and will thereby rotate the lever B in a clockwise direction from its normal position tothe position in which it is shown in the drawing, which latter position we shall term its braking position. This rotation of the lever moves the spring seat ll toward the right, as viewed in Fig. 1, to a position in which the spring 12 becomes compressed beyond its initial compression, and also causes a rotating motion between the points of contact of the lever with the spring seat. This rotation of the lever also causes the spring bolt 9 to swing downwardly a slight amount about the points of contact between its head So and the arm 3d, as will be obvious. The braking forces which are exerted on the car will of course depend upon the stifiness and the amount of initial compression of the spring l2, and may be adjusted by adjusting the bolts l5 and I6 in the manner pointed out hereinbefore,

It should be particularly pointed out that in a car retarder of the type described it is essential that the lower end of the lever 6 should remain in firm contact with the lugs I when no car is in the retarder for three reasons. In the first place, if the lower end of the lever is allowed to swing out of engagement with the lugs 1 when no car is in engagement with the retarder, the position which the upper end of the lever, and hence the brake shoe 5, will assume is likely to vary, which makes it diflicult to adjust the retarder. In the second place, if the lower end of the lever is allowed to swing away from the rail, the recoil of the spring I2 when a car leaves the retarder is likely to cause the brake shoe 5 to swing closer to the rail than is desirable, and as a result when a car next starts to enter the retarder, it will strike the end of the brake shoe with a greater force than intended, and thereby damage the retarder. In the third place, if the lower end of the lever is out of engagement with the lugs I when a car starts to enter the retarder, the force set up by the wheels striking the brake shoe will swing the lower end of the lever into engagement with the lugs with a hammerlike blow, which will cause excessive stress and wear.

In accordance with our present invention we retain the lower end of the lever in the desired position by locating the holes 6e and 6f in the lever through which the bolts I5 and I6 which adjust the initial compression of the spring l2 pass in such positions that the nuts I! will engage the lever along a horizontal line of contact which is disposed vertically above the axis of the spring bolt 9. With the parts arranged in this manner, when no car is in the retarder,

the spring l2 will apply to the lever on the side nearest the rail a force acting along a line disposed above and inclined to the axis of the bolt '9 which force, together with that acting on the outer side of the lever along the axis of the bolt, produces on the lever a mechanical couple Which is effective to maintain the lower end of the lever in firm contact with the lugs I.

If it is desired to render the retarder inactive for any reason, this may be done by backing oil the nut M a few turns. This will allow the lever to swing due to its gravity bias to a position in which the brake shoe is out of the path of car wheels traversing the rail I. i

It should be pointed out that when the brake shoe 5 becomes worn, this wear can be compensated for by adjusting the nut M, as will be obvious. It should be particularly noted that this adjustment will not affect the forces which hold the lower end of the lever in engagement with the lugs 1.

Referring now to Figs. 3 and 4, in the modified form of retarder here shown the braking bar B is supported for swinging movement toward and away from the rail I by means of a cast lever 25 provided at its lower end with a channel shaped recess 250. which loosely receives the base flange of the rail I in such manner that the lever is free to pivot about the base flange as a fulcrum. The

brake beam 4 and brake shoe 5 of the braking bar are secured to the lever 25 by means of bolts and 23, respectively, in the same manner as they are secured to the lever B in Figs. 1 and 2.

Formed in the lever in axial alignment with an opening H] in the rail web is an opening 251]; and extending with clearance through the aligned openings [0 and 25b is a spring bolt 26, the lefthand end of which, as viewed in Fig. 3, is provided with a bearing sleeve 2'! and a nut 28, and

the right-hand end of which is provided with an U inner spring seat 29 similar to the spring seat I! in Figs. 1 and 2, a compressed coil spring I2, an outer spring seat 30 and a nut 3|.

The bearing sleeve 21 is provided with a depending portion 2'la' which cooperates with the base flange of the rail to prevent rotation of the sleeve relative to the spring bolt in response to rotation of the nut 28, and with rounded surfaces 212) on opposite sides of the bolt about which the sleeve is intended to roll to permit the spring bolt to rock in response to rotation of the lever 25. The outer end of the bearing sleeve is provided with rounded bulges 210 which enter correspondingly shaped recesses 280. provided in the adjacent face of the nut. The normal position of the lever, that is to say, the position when no car is passing through the retarder, is determined by adjusting nut 28, which nut also provides a means for adjusting for brake shoe wear,

and the cooperating. bulges 21c and recesses 28a provide a convenient means for locking the nut 28 against rotation to prevent loss of adjustment due to vibration and the like.

To permit adjustment of the initial compression of the spring l2, the spring bolt 26 is provided between the rail and the lever with a shoulder 32 which, when no car is in the retarder, engages the inner face of the lever at rounded portions 25d formed on the lever on opposite sides of the bolt. Adjustment of the initial compression of the spring l2 may be made by means of the nut 3|, as will be obvious.

The operation of the retarder as a whole when constructed as shown in Figs. 3 and 4 will be apparent in general from the foregoing description of Figs. 1 and 2. It should be particularly pointed out, however, that in accordance with our present invention we so locate the rounded portions 25d which are provided on the lever that the points of contact between the shoulder 32 and these rounded portions when no car is in the retarder will occur along a horizontal line disposed vertically above the axis of the bolt 26, whereby when no car is passing through the retarder, the spring I2 will apply to the lever on the side nearest the rail 2 force acting along a line disposed above and inclined to the axis of the bolt 26, which force, together with that acting on the outer side of the lever along the axis of the bolt, produces on the lever a mechanical couple of forces which areefiective to maintain the lower end of the lever in firm engagement with the rail flange without the necessity for any other means for this purpose. It should also be pointed out that adjustment of the nut 28 to compensate for brake shoe wear will not materially afiect this couple, so that" when the proper initial compression of the spring [2 has once been obtained, it is not necessary thereafter to further adjust the nut 3|.

Although we have herein shownand described only two forms of car retarders embodying our invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of our invention. 5

Having thus described our invention, what we claim is:

1. Railway braking apparatus comprising a lever disposed at one side of a track rail for swinging movement toward and away from. the rail and provided at its upper end with a braking bar extending parallel to the rail, means including a spring bolt and a spring disposed on said bolt for normally exerting on said lever a force which biases said lever to a braking position in whichsaid braking bar will frictionally engage the wheels of a car traversing said rail, and other means carried in part by said bolt and in part by said lever and effective when no car wheel is engaging said braking bar for causing said spring to exert on said lever a mechanical couple which is effective to maintain the lever in firm engagement with the point about which it swings.-

2. Railway braking apparatus comprising a lever disposed at one side of a track rail for swinging movement toward and away from the rail and provided at its upper end with a braking bar extending parallel to the rail, means including a spring bolt and a spring disposed on said bolt for normally exerting on said lever a force which biases said braking bar to a position in which it will frictionally engage the wheels of a car traversing said rail, and means carried by said bolt and engaging said lever at a point offset from the axis of said bolt when no car wheel is engaging said braking bar for applying to said lever by means of said spring along a line inclined to the axis of the bolt a force which together with the spring force acting on the lever along the axis of the bolt produces a mechanical couple which is effective to maintain said lever in firm contact with the point about which it swings. v

3.-R.ailway braking apparatus comprising a. lever disposed at one side of a track rail for swinging movement toward and away from the rail, said lever being loosely supported at a point below the rail web by means which limits movement of the lever toward the. rail at its point of support, means including a spring and a spring bolt for applying to said lever a force which urges said lever toward the rail to a predetermined position, said lever being biased away from the rail by gravity, and other means carried in part by said lever and in part by said bolt for applying to said lever by means of said spring along a line disposed above and inclined to the axis of said bolt a force which together with the force applied to said lever along the axis of said bolt exerts on said lever when no car wheel is engaging said braking bar a torque which urges said lever toward the rail at its point of support to limit wear between the parts.

4. Railway braking apparatus comprising a lever loosely pivotally supported at its lower end at one side of a track rail for swinging movement toward and away from the rail and provided at its upper end with a braking bar extending parallel to the rail, said lever being provided with an opening which aligns with an opening provided in the web of the track rail, a spring bolt extending through said openings with clearance and provided at the end disposed at the outer side of said lever with a nut and at the opposite end with means for preventing axial movement in one direction, a spring disposed on said bolt between said lever and said nut for applying to said lever at its outer side a force which biases the lever toward the rail to a position in which said braking bar will frictionally engage the wheels of cars traveling said rail, a spring seat disposed on said bolt and engaging the outer end of said spring, and means including two bolts extending loosely through apertures provided in said spring seat and openings formed in said lever and carrying means engaging said lever along a horizontal line disposed above the axis of said spring bolt for at times applying to said lever by means of said spring a mechanical couple which is effective to prevent lost motion between said lever and its support.

5. Railway braking apparatus comprising a track rail mounted on a rail support and provided with an opening in the rail web, a lever resting at its lower end on said rail support between spaced lugs which loosely limit movement of the lower end of saidlever toward or away from the rail and provided at its upper end with a braking bar for frictionally engaging the wheels of a car traversing said rail, said lever being provided with an opening aligning with the opening in the rail web, an arm on said rail support on the side of the rail opposite to said lever, said arm being provided with a slot aligning with the openings in said rail web and said lever, a bolt extending through said slot and said openings and provided with a head which engages said arm at the side farthest away from the rail, a nut screwed onto said bolt at the end opposite to its head; a spring disposed on said bolt between two spring seats one of which engages said nut and the other of which engages said lever at its outer side, diametrically opposite apertured lugs provided on the spring seat which engages said nut on opposite sides of said bolt, holes formed in said lever on opposite sides of the opening which receives said spring bolt at points located vertically above the axis of said spring bolt, and other bolts passing through the apertures in said lugs and the holes in said lever and provided with means engaging the inner face of said lever along a line disposed above the axis of said bolt, whereby a force is at times applied by means of said spring and said other bolts to said lever at the side nearest the rail along a line inclined to the axis of said spring bolt which force together with the spring force acting along the axis of the bolt produces a mechanical couple which is effective to maintain the lower end of said lever in firm contact with the lugs which limit movement of this end of the lever toward the rail.

6. Railway braking apparatus comprising a lever disposed at one side of a track rail and provided at its lower end with a recess which receives the base flange of the rail in such manner that the upper end of said lever is free to swing toward and away from the rail about the base flange as a fulcrum, said lever being provided intermediate its ends with an opening which aligns with an opening provided in the web of the track rail, a braking bar secured to the upper end of said lever, a spring bolt extending with clearance through said opening and provided at each end with a nut, a spring disposed on said bolt between said lever and the adjacent nut and effective to bias said lever toward the rail to a position in which said braking bar will frictionally engage the wheels of cars traversing said rail, and means on said bolt between the rail and said lever adapted to engage the inner side of said lever along a line disposed above the axis of said bolt when no car wheel is in engagement with said braking bar to cause said spring to exert on said lever a mechanical couple which holds the lower end of the lever in engagement with the base flange of the rail.

KENNETH J. J. MCGOWAN. HERBERT L. BONE.

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