US2903096A - Railway car brake mechanism - Google Patents

Description

Sept. 8, 1959 Filed March 3, 1955 C. R. BUSCH RAILWAY CAR BRAKE MECHANISM ll Sheets-Sheet 1 INVEN OR BY M M, ATTO R N EY Sept. 8, 1959 Filed March 3, 1955 C. R. BUSCH RAILWAY CAR BRAKE MECHANISM 11 Sheets-Sheet 2 INVENTOR 4/9151 1?. 191mm.

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RAILWAY CAR BRAKE MECHANISM I Filed March 5, 1955 l1 Sheets-Sheet 11 INVENTOR CHARLH'R BuscH.

ATTORNEYS.

United States Patent RAILWAY CAR BRAKE MECHANISM Charles R. Busch, Orange, NJ., assignor to Buffalo Brake Beam Company, a corporation of New York Application March 3, 1955, Serial No. 491,838

Claims. (Cl. 188-59) The present invention relates to railway car brake mechanism, especially of the freight type.

The conventional railway freight car has two trucks, each carrying four wheels arranged into two sets of coaxial wheels. Each truck comprises a pair of side frames, a bolster or transom between said frame connected to the railway car body and spring supported on said side frames for guided vertical movement, two parallel axles journalled in said side frames for two sets of coaxial wheels, two brake beams extending between and movably supported from said side frames, these brake beams having brake heads at their ends with metallic brake shoes for direct application to the peripheries of the wheels in braking position, and linkages applying power to the beams along their center lines to operate the beams towards the corresponding wheels for braking action. The heat generated by the metallic brake shoes on the peripheral faces of the car wheels causes brake burns, burnt car wheel flanges and outer rim cracks on the tread of the wheel and in many cases is severe enough to cause the wheels to break and to result thereby in serious accidents.

Another disadvantage of this brake beam type of railway car brake device is that the brake shoe pressure on the wheels necessary for effective braking has become so great with the present advent of heavy freight cars and high speeds that this pressure exerted on the wheels unseats the journal bearings from the journals, causing thereby hot boxes and resulting in delay and damage to equipment.

Another disadvantage of this conventional type of brake beam arrangement is that the device for operating the brake beams towards and away from their corresponding wheel axles includes a live lever for operating one brake beam in a truck and a dead lever for operating the other brake beam in said truck. One end of the dead lever is attached to the car body or to the truck bolster, so that its pivot support is rigid with respect to said car body or bolster and, since the car body through the bolster is spring-supported on the side frames of the trucks, the car body is permitted to yield vertically against spring resistance. The resulting stresses are transmitted to the brake beams through the dead lever, and since these beams are supported from the side frames without allowing for their vertical movement, these stresses may damage the brake beams and also the car wheels while the brakes are being applied.

One object of the present invention is to provide a new and improved railway car brake device which overcomes the aforesaid and other disadvantages.

Another object of the present invention is to provide a new and improved railway car brake device, which is of the rotor brake disc type, in which the brake shoes are applied against the faces of friction discs rotatable with respective Wheels for braking action, which is comparatively simple in construction and inexpensive to manufacture, which eliminates the use of the usual heavy trusslike brake beams conventionally employed in connection with railway freight car brake devices, which can be employed without material change in the basic construction of certain elements of the conventional railway truck, such as the side frames, bolster, wheel mountings and the spacing of these elements in the trucks, which are so designed and mounted as to avoid destructive stresses on certain vital elements of the car truck as a result of the vertical spring resisted vibrations of the car, which assures uniform braking action on all four wheels of a railway truck regardless of unequal wear on the braking parts associated with the four wheels, which allows for adjustment in the braking parts associated with any one wheel in relation to the braking parts associated with any other wheels in a railway car truck to compensate for any undue wear in any one set of braking parts, which eliminates the use of a separate power cylinderfor braking action on each wheel as required in certain prior art railway brake devices and allows the use of one air power cylinder for the effective braking of all of the eight wheels on each car, and which is designed to alford interchangeability in the braking parts associated with the different wheels.

In accordance with one feature of the present invention, there are provided for each car truck four linkages which operate brakes against brake discs rotatable with respective car wheels and which are powered from a single source. These linkages are supported on the side frames, so that they are held against vertical movement relative to said side frames, thereby assuring constant brake pressure on the discs during a brake application, while the source of power, which may consist of standard air brake equipment with associated air cylinder and cylinder lever, is connected to the body of the railway car for vertical movement therewith. To permit free spring suspension of the car body through bolsters resiliently supported on side frames, without transmitting the vertical movements of the car body to the braking discs and to other parts of the braking linkages and without interfering with effective transmission of braking power to and through said linkages, there are provided flexible connections between the source of power and the power input sides of these linkages.

In accordance with another feature of the present invention, the four linkages in a car truck are so designed and so interconnected as to assure uniform braking on all of the brake discs of each car truck, in spite of the usual wear in the brake shoe or brake disc associated with any one car wheel of the car truck.

As another feature of the invention, adjusting means are provided to compensate for excessive wear in any one brake unit of a car truck to assure uniform braking on all of the brake discs of each car truck, in spite of such excessive Wear.

As a further feature of the invention, each of the linkages of a car truck comprises a brake head lever of L-shape, having one leg extending along the bolster substantially midway between the bolster and the adjacent car wheel and pivotally secured to a bracket afiixed to the adjoining side frame, While the other leg extends transversely of the bolster and carries the brake head for the brake shoe. This arrangement permits accommodation of the improved braking device in the limited spacing allowed between certain of the basic elements of a conventional car truck retained for the car truck of the present invention.

As a further feature, the brake shoe is connected to the brake head on the L-shaped brake head lever through a rocker and swivels with the rocker to compensate for the arcuate swing of the lever about its pivot support, thereby assuring uniform braking pressure against the full area of the brake shoe.

As a further feature, the opposed brake head levers on opposite sides of the bolster are connected by a push rod extending through the bolster and having pivotally supported ends protectively housed in said levers. This con- StIHCtion and arrangement reduce materially the chances of the pivot pins at the ends of the push rod falling out of the push rod and of causing accidents thereby. In case the push rod should become loose and disengaged, it'will be supported in the bolster in safe position, until the failure can be discovered and corrected.

Various other objects, features and advantages of the invention are apparent from the following particular description and from the accompanying drawings, in which:

Fig. 1 is in general a top plan view of a railway car truck having braking features embodying the present invention, some of the parts of the truck being shown broken away to reveal some of the interior structure of the truck;

Fig. 2 is a vertical section of the railway truck taken on lines 2--2 of Fig. 1, but shown on a larger scale;

Fig. 3 is a detail vertical section of the railway truck taken on lines 3-3 of Fig. 1, but shown on a larger s a 4 is an enlargement of a part of Fig. 1, showing the braking device in connection with a single car wheel;

Fig. 5 is an enlargement of a part of Fig. 2, showing the braking device in connection with a single car wheel;

Fig. 6 is a detail section of the brake head and associated brake shoe assembly taken on lines 6-6 of Fig. 5;

Fig. 7 is a face view of part of the inboard side of the brake rotor disc indicated in Fig. l but shown on a larger scale;

Fig. 8 is a section of the brake rotor disc taken on lines 8-8 of Fig. 7;

Fig. 9 is a face view of part of the outboard side of the brake rotor disc of Figs. 7 and 8;

Fig. 10 is a section of the brake rotor disc taken on lines 10-10 of Fig. 9 but shown on a larger scale;

Fig. 11 is a face view of the brake head indicated in Fig. 1 but shown on a larger scale, with parts broken away to reveal the interior structure of the brake head;

Fig. 12 is a section of the brake head taken on lines 12-12 of Fig. 11;

Fig. 13 is a face view of a rocker forming part of the brake head-shoe assembly and permitting swivelling movement of the brake shoe attached to the rocker, in the application of the brake;

Fig. 14 is a section of the rocker taken on lines 14-14 of Fig. 13;

Fig. 15 is a face view of the brake shoe lining plate;

Fig. 16 is a section of the brake shoe lining plate taken on lines 16-16 of Fig. 15 and showing in conjunction therewith U-shaped clips by which this lining plate is removably atached to the rocker of Figs. 13 and 14;

Fig. 17 is a perspective of the metal clips shown in Fig. 16;

Fig. 18 is a face view of the brake shoe;

Fig. 19 is a section of the brake shoe taken on lines 19-19 of Fig. 18;

Fig. 20 is a side view of the brake shoe key by which the brake shoe and brake head are interlocked;

Fig. 21 is a detail section of the brake shoe and brake head in assembled position;

Fig. 22 is a face view of part of the outboard side of a modified form of brake rotor disc;

Fig. 23 is a radial section of the brake rotor disc of Fig. 22 taken on lines 23-23 thereof;

Fig. 24 is a detail section of the brake rotor disc of Figl. 22 taken on lines 24-24 thereof but on a larger .9 c;

Fig. 25 is a face view of part of the inboard side of another, modified form of brake rotor disc in which the disc isjconnected directly to the rim of the corresponding car wlfieei, sai-d'disc being shown in conjunction with the w ee;

. Big, 26 a radial section of the assembled car wheel 4 and brake rotor disc of Fig. 25 taken on lines 26-26 thereof;

Fig. 27 is a face view of part of the inboard side of still another modified form of brake rotor disc in which the disc is connected directly to the corresponding car wheel, said disc being shown in conjunction with the wheel;

Fig. 28 is a radial section of the assembled car wheel and brake rotor disc of Fig. 27 taken on lines 28-28 thereof;

Fig. 29 is a face view of part of the inboard side of a still further modified form of brake rotor disc and of the corresponding car wheel to which it is integrally connected;

Fig. 30 is a radial section of the car wheel and brake disc unit of Fig. 29 taken on lines 30-30 thereof;

Fig. 31 is a detail vertical section of .a railway truck containing a modified form of brake rotor disc and taken on lines 31-31 of Fig. 32;

Fig. 32 is a detail vertical section of the modified form of railway truck shown in Fig. 31 taken on lines 32-32 thereof;

Fig. 33 is a top plan view, partly in section, of a detail of the modified form of railway truck shown in Figs. 31 and 32;

Fig. 34 is a top plan view, partly in section, of a modified form of linkage system operating the brakes on adjoining brake discs on opposite sides of the bolster;

Fig. 35 is a top plan view of a modified form of beam arrangement for transmitting power to the linkages operating the brakes on one side of the bolster;

Fig. 36 is a detail section of the beam arrangement of Fig. 35 taken on lines 36-36 thereof;

Fig. 37 is a side view of the beam arrangement of Figs. 35 and 36; and

Fig. 38 is a section of the beam arrangement of Figs. 35, 36 and 37 taken on lines 38-38 of Fig. 36.

Referring to Figs. 1 to 21 of the drawings, and more specifically to Figs. 1-6, there is shown a railway freight car truck comprising a pair of side structures 10 constituting side frames and having respective guide openings 11 to receive the ends of a bolster 12 extending between said frames and projecting at the ends into said openings, where they are supported on coil springs (not shown) and are guided by side columns 13 of said openings for vertical shock-absorbed movement. The bolster 12 has a center conformation .14 for direct pivotal connection to the underside of the railway car body. Between the two side frames 10 and supported thereon by suitable bearings are two parallel axles 15 carrying at opposite ends flanged car wheels 16 which ride on rails 17.

The bolster 12 is provided at the ends with lugs '18 and 19 engaging the side columns 13 of the side frames 10 for vertical guided movement therealong. As will be made apparent, the brake mechanism of the present invention has a tendency to pull the side frames 10 inwardly, and the lugs 19 on the bolster 12 permit the bolster to be used effectively as a compression member, thereby holding the side frames in correct position on the center lines of the journals. The size of these bolster lugs 19 may be increased from conventional practice to add sufficient strength to the bolster to accept this compressive action.

The car truck construction, to the basic extent to which it has been described above, is of conventional form in brake beam types of car trucks, as exemplified in US. Patent No. 2,518,120. In such a construction, the spacing between the bolster 12 and the car wheels 16 is very limited and, if this spacing is to be retained for rotor disc types of car brake, this poses a serious problem. In accordance with the present invention, the brake device is designed to permit the retention of this spacing of the basic elements of the truck. 3

In accordance with certain features of the present invention, the brakes for the four car wheels 16 of each car truck are operated by four sets of linkages 20 interconnected and actuated from a single source of power, as will be described. These brake operating linkages 20 are supported from respective brackets 21 flanking the bolster 12 and rigidly connected to the side frames on opposite sides of the bolster guide opening 11 on said side frames. These brackets 21 can be forged or pressed and welded to the side frames 10 and each bracket is in the form of an L having a short leg 22 rigidly connected to a corresponding guide bolster column 13, and extending along the corresponding side frame and a longer bracket leg 23 extending inwardly and transversely of said side frame substantially midway between the bolster 12 and the adjacent car wheel 16.

Each brake operating linkage 20 comprises a brake head L-shaped lever 25, one leg 26 of which is pivotally connected at 27 to the end of the bracket leg 23, the other leg 28 carrying at its end a brake head 29, to be more fully described. As far as certain aspects of the invention are concerned, the lever 25 may have a third leg extension as shown in the lever 117 in the modification of Fig. 34, but this modified lever is still considered to be an L-shaped lever but with a third leg extension. For providing a pivotal connection of ample strength between the brake head lever 25 and the bracket 21, this connection is in the form of a knuckle joint and to that end, the bracket has a pair of spaced projections 30 (Fig. 3) entering jaws in the lever leg 26 formed by three space projections 31, these projections being retained in interconnected pivotal relationship by a hinge pin 32 passing through eyes or openings in said projections and presenting large bearing surfaces. These openings are preferably lined with hardened bushings to protect them from wear.

The brake head lever 25 can be cast, forged or otherwise formed into the desired shape, and except at its ends, it is of U-shape cross section for structural strength and for the purpose to be made apparent. At the brake end of the lever 25, the lever has rigid therewith the brake head 29 (Figs. 1, 2, 4, 5 and 6) which is preferably integral with the lever, but which, as far as certain aspects of the invention are concerned, could be a separate piece riveted or bolted to the lever. The brake head 29 carries a shoe 33 for application to a brake,

rotor or disc 34 affixed to the corresponding axle near the corresponding car wheel 16.

Each car truck has four similar brake head levers 25 symmetrically arranged for action on four rotor brake discs 34, respectively. To actuate the brake head levers 25 for uniform braking action on the respective brake discs 34, there is provided for each pair of opposed brake head levers 25, on opposite sides of the bolster 12, a parallel device comprising a pair of parallel brake arms 35 and 36 of equal lengths, pivotally joined intermediate their ends to the elbows of the brake head levers 25 at 37 and pivotally interconnected at one end by a connecting push rod 38 passing through the bolster 12. At their other ends, the brake arms 35 are power actuated through a power input member 40 in the form of a bridle beam, in a manner to be described, while the other brake arms 36 are fulcrumed against brackets 41 affixed to the side of the bolster 12.

The bolster 12 is of hollow substantially rectangular construction, but opposite vertical walls thereof near each end are provided with alined openings 45 to allow the free passage therethrough of the corresponding push rod 38. Near the region of these openings 45, the bolster is internally provided with reinforcing vertical ribs 46 to compensate for the weakening of the bolster by themevision of these openings.

. The brake head levers 25 are arranged so that the open sides of their legs 26 of U-shaped cross section face the bolster 12, and the ends of each push rod 38, where it is pivotally connected to the associated brake arms 35 and 36, ,extend into and are housed in the cavities of the legs 6 26 of said brake arms. The ends of each push rod 38 are shown forked in Figs. 2, 3 and 5 to receive the flat ends of the brake arms 35 and 36 between the projections of the fork. Pins 47 (Fig. 1) hold the ends of the brake arms 35 and 36 in pivotal knuckle relationship to the ends of the push rod 38. The pivot pins 47 are housed in the cavities of the brake head levers 25 between the opposite walls thereof and are thereby protectively held against accidental withdrawal and disengagement from their retaining holes. In any case, if the pivot pins 47 should be disengaged from the push rods 38, no serious accident can result, since the push rods extend through the bolster 12 and cannot fall into position to cause serious accidents or breakages in the truck structure. EX- treme safety is thereby assured.

Each push rod 38 at one end has a fixed pivot connection with the brake arm 35. However, at the other end, the push rod 38 has one or more additional adjusting holes 48 (Fig. l) to extend the pivotal connection for the brake arm 36 to compensate for undue brake shoe wear. This is desirable for the air brake cylinder piston which powers all of the braking units of each car truck, because this piston has only a limited travel and brake shoe wear can be compensated in a most practical manner by extending the effective length of the push rod 38. This adjustment can be made by a repair man by working over the side frames 10, without going underthe car.

At the elbow of each brake lever 25, where it pivotally connects into the intermediate sections of the corresponding brake am 35 or 36, this elbow is provided with bosses 50 (Figs. 2 and 5) extending inwardly from opposite wallsof the brake lever to receive therebetween, with a snug pivotal fit, the flat intermediate section of said brake arm and to receive a hinge pin 51 (Fig. 1), while aflording large bearing areas for said pin.

Power is applied to the brake arms 35 on each car truck through the beam 40-. This beam 40 extends horizontally across the center line of the car truck, with its middle point on said center line, and at this point it is connected to a short arm- 52 (Figs. 1 and 4), one end of which is secured to this middle point of the beam 40, while the other end is pivotally connected to the lower end of lever 53 extending obliquely upwardly. The upper end of the lever 53 is pivotally connected to the bolster 12 or to the underside or body 49 of the railway car, as shown in Fig. 4. The lever 53 is power-actuated by a pull rod 54 pivotally connected to the intermediate section of the lever 53 at 55 and operated from the lever (not shown) of the air cylinder (not shown), supported in the usual manner on the car body and forming part of the conventional air brake equipment.

Since the brake head levers 25 and the brake arms 35 and 36, forming part of the linkages 20, are supported on the side frames 10 against vertical movement by the mounting brackets 21 aflixed to said side frames, and since the beam 40 (associated pull rod 54), lever 53 and air brake cylinder are attached to the car body and therefore are vertically movable with said car body through the bolster spring supports, flexible connections are provided between the ends of the beam 40 and the inner ends of the brake arms 35 to allow for relative vertical movement between the braking parts of the mechanism and the power applying parts. Each of these flexible connections includes a link 57 in the form of an elongated loop pivotally coupled at its ends to the ends of the beam- 40 and the ends of the brake arms 35 by means of c-levises or shackles 60.

The bridle arrangement with the flexible connections described, permits the car body with the air brake equipment attached thereto to move up and down against the shock-absorbing action of the springs on the side frames 10 supporting the bolster 12, without transmitting these movements or the stresses therefrom to the brake head levers 25 and in turn to the brake shoes 33 carried thereby, and without disturbing the transmission or full braking power to said shoes from the air brake equipment.

Since the bolster 12 is secured to the car body and spring supported in the side frames for vertical movement and since the brake arms 36 are held against vertical movement by their support from the side frames 10 through the brackets 21, the brackets 41 on the bolster 12 (against which the free ends of the brake arms 36 bear) serve as fulcrums for said brake arms, as already described; and in order to permit the up and down movements of the bolster without interfering with the transmission of full braking power, the free ends of these brake arms are provided with rounded vertical guide channels 63 (Fig. 1) and the brackets 41 are provided with vertical side flanges 64 seating in said channels and rounded ofl? at their outer edges to permit smooth angular movement of said brake arms about said flanges. With this arrangement, not only are the brake arms 36 fulcrumed about the brackets 41 in their transmission of braking power to the brake head levers 25 connected thereto, but moreover the brackets 41 are permitted to move vertically with respect to the brake arms 36, due to the vertical spring-resisted movements of the bolster 12, without interrupting the fulcrum connection between the brackets 41 and the brake arms 36.

The brake is applied to each rotor brake disc 34 which, in the form shown in Figs. 1-21, is separate from the corresponding car wheel 16 but is rigidly connected to the corresponding axle 15 or car wheel 16 for rotation therewith. Each rotor disc 34 (Figs. 1-10) may be made as a casting, forging, pressing or the like and consists of a circular disc presenting on its inboard side a flat circular radial braking surface 67 (Figs. 4, 7-1()) against which the brake shoe 33 is applied for braking action. On its outboard side, the rotor brake disc 34 has integral therewith a series of radial fins 68 opposite the braking surface 67 to dissipate the heat generated on the disc from the brake shoe 3-3. The outboard side of the rotor brake disc 34 also has a series of radial reinforcing ribs 70.

The rotor brake disc 34 is affixed to the axle 15 in any suitable manner, as for example, by means of studs 71 threaded into the hub 72 of the corresponding adjacent car wheel 16.

The leg 28 of each brake head lever 25 integrally carries the brake head 29, as previously described. This brake head 29 is in a general form of the segment of an annulus and is located opposite the braking surface 67 on the brake disc 34. The active face of the brake head 29 is of sufficient width and length to provide ample brake shoe surface.

Since the brake head lever 25 moves angularly about its pivot support at 27 on the bracket 21, the outer face ofthe brake head 29 changes its angularity with respect to the plane of the braking surface 67 on the brake disc 34 as the brake head lever 25 is moved angularly into braking position. To provide, under these conditions, full and even wear of the brake shoe 33 as well as application of equal pressure across the entire face of the shoe during brake application, there is provided a rocker 75 (Figs. 4, 5, 6 and 11-21) pivotally secured to the brake head 29 and presenting a face to which the brake shoe 33 is. secured. To mount the rocker 75 in position, the brake head 29 at the end of the lever leg 28 has a series of sockets 76 (three being shown) of substantially circular contour at their bases, and the rocker 75 has a corresponding number. of circular lugs 77 extending into said sockets andv seated against the rounded surfaces at these bases,.to transmit pressure thereby from the brake head 29 to the brake shoe 33. The lugs 77 on the rocker 75 are provided with alined holes 80,. which register with alignedholes 81v in. the brake head 29 to receivea brake shoeikey. 82 inthe form of a round metal rod having a bent head 83 at one end and carrying a cotter 84 at its other end, to hold the key in position.

To permit the rocker 75 to cradle on the brake head 29, the sockets 76 on said brake head are wider at their mouth than the lugs 77 of said rocker seated therein as shown in Fig. 21, and the back face 86 of said rocker slants from the lugs 77 sideways away from the front face 87 of said brake head to aflord the necessary clearance to permit the rocker to swivel substantially about the axis of the key 82. Thus the rocker 75 will, by its swivelling action, compensate for the movement of the brake head lever 25 along an arc to and from the face of the brake disc 34, thereby affording even wear of the brake shoe 33 as well as equal pressure during a brake application.

The brake shoe 33, made of metal or of suitable brake lining material, is expended through wear from friction in its brake application and must be replaced from time to time. The shoe 33 is therefore removably secured to the rocker 75. For that purpose, the shoe 33 is secured to a thin metal lining plate 90 by rivets or other suitable metal fastening elements 91, as shown, or if desired by adhesive. This shoe lining plate 90 has a series of lugs 92 (three being shown), preferably stamped out therefrom and each flanked by a pair of openings 93 in said plate. The rocker 75, at the bases of the lugs 77 thereon, is provided with recesses 94 into which the lugs 92 'of the shoe lining plate 90 nest, and the rocker is provided with a pair of elongated openings 95 flanking each lug on said rocker. To lock the shoe lining plate 90 to the rocker 75, there are provided U-shaped metal clips 96, which straddle the lugs 92 on said shoe lining plate and the lugs 77 on said rocker, which pass through the openings 93 in said plate and openings 95 in said rocker, and which are retained in position by means of the shoe key 82 passing through said clips. The clips 96 serve not only to lock the shoe lining plate 90 with attached shoe 33 to the rocker 75 but also as bearing plates between the intermeshing parts of the rocker 75 and the brake head 29. By removing the key 82, the clips 96 can be pulled out and the shoe lining plate 90 removed from the rocker 75 for replacement of the worn shoe 33 on said plate.

During the application of the shoes 33 to the brake discs 34, these brake shoes tend to be shifted in the direction of rotation of the discs. In a 4-wheel truck, one pair of wheels on the truck are revolving downward, whereas the opposite wheels are moving upward, therebyexerting both up and down pressure depending upon the rotation of the wheels. To assist in holding the brake shoes 33 against pressure upward or downward of the brake discs 34, each brake lining plate 90 has a peripheral flange or lip 97, and the rocker 75 is sufliciently smaller than said lining plates to fit snugly into the recess defined by the dishing of the lining plate as described. The flange 97 on the shoe lining plate 90 engages the upper and lower edges of the rocker 75 and thereby assists in holding the brake shoe against the up or down pressure exerted thereto by the brake disc 33.

In the operation of the brake mechanism of Figs. 1 to 21, when the usual air cylinder lever is actuated to apply the brakes, power is transmitted from the air cylinder through said cylinder lever to the pull rod 54 (Figs. 1 and 4), causing said rod to move towards the left. This causes the lever 53, pivotally suspended from the car body, to move angularly towards the left about its upper pivot support and the horizontal beam 40 to move horizontally towards the left. Since the beam 40 is pulled at its center by the mechanism described, this exerts equal pull at the ends of the beam towards the left, this pull being transmitted to the two brake arms 35 on one side of. the bolster 12 through the flexible connections 57, 60. Considering the linkage 20 shown in Fig. 4 and the corresponding linkage 20 in-Fig. I, pull on the-brake arm 35 atone end towards the left causes said brake-arm to swing horizontally clockwise about its support at 37 at the elbow of the brake head lever 25. Since at the other end of the brake arm 35, this clockwise movement of the brake arm about its support at 37 is resisted by the push rod 38 connected thereto at this end and operating the other brake linkage on the opposite side of the bolster 12, the pull on the brake arm 35, as described, also causes the brake head lever 25 to swing horizontally clockwise about its pivot support at 27 on the bracket 21, thereby moving the brake shoe 33 carried by said lever against the brake disc 34 and braking the corresponding car wheel 16. It should be noted that during this braking action, the pivoted ends of the push rod 38 do not leave the housing protection of the brake head levers 25, so that the pivot pins at the ends of this push rod are retained against accidental disengagement.

During the braking action just described, the brake shoe 33 swivels through its rocker connection to the brake head 29, to compensate for the arcuate course travel by said shoe in its approach to the corresponding brake disc 34, thereby assuring continuous face to face contact of the shoe with the braking surface of said disc.

Theoretically, the four brake units in each car truck should reach braking position at the same time. Assuming, however, that the brake shoe 33 on the upper left hand side of the car truck shown in Fig. 1 reaches full braking position before the brake shoe on the upper right hand side of the car truck, due for example to differences in Wear or to manufacturing tolerances, as soon as the brake shoe on the upper left hand side has been stopped by the corresponding brake disc 34, this anchors the pivot support for the 'brake arm 35 at 37 on the corresponding brake lever 25 in fixed position relative to the side frames 10, so that the brake arm 35 continues to move solely about the said pivot sup port clockwise to impart its full power to the push rod 38. Power from the push rod 38 is transmitted towards the right to the brake arm 36 of the linkage on the opposite side of the bolster 12 (Fig. 1). Since one end of this brake arm 36 is fulcrumed about the slide flange 64 of the bracket 41 secured to the bolster 12, the thrust of the push rod 38 on said brake arm 36 swings the brake arm clockwise about said flange, causing the brake head lever connected thereto at 37 to swing counterclockwise about its pivot support at 27 on the bracket 21. This moves the brake shoe 33 carried at the free end of the brake head lever 25 against the corresponding brake disc 34.

It is also possible, due to wear or mechanical tolerance, for the brake shoe 33 on the upper right side of the car truck (Fig. 1) to be applied before the brake shoe 33 on the upper left hand side of the car truck. In that case, after the brake head lever 25 at the right has been stopped in braking position, continued movement of the pull rod 54 towards the left causes the brake arm 35 to swing clockwise about its stopped pivot support at the end of the push rod 38, thereby causing the brake head lever 25 at the left pivotally connected to said brake arm 35 to swing clockwise about its pivot support at 27 on the bracket 21, until the brake shoe 33 on the free end of said brake head lever at the left moves into braking contact with the corresponding brake disc 34.

Whether the two interconnecting linkages 20 on opposite sides of the bolster 12 are operated simultaneously orsuccessively as described, they are substantially operated at the same time and the pressure applied to the shoes 33 of both linkages is the same, due to the similarity of the two brake head levers 28 and the parallel nature of the mechanism 35, 36 and 38. The other two linkages 20 on the lower side of the truck shown in Fig. 1 are similarly operated from the pull rod 54.

During the air powered brake operations described, vertical movements of the car body are not transmitted to the brake shoes 33, because of the flexible connec- 10 tions 57, 60. These connections permit vertical movement of the power input end of the mechanism and with the car body relative to the linkages 20, without interrupting the transmission of braking power to the braking shoes 33.

Another advantage gained by this arrangement is that when the hand brake is used in the usual conventional manner instead of the air power brake (as, for example, for prolonged braking periods during loading), the brake shoes 33 remain constant in their applied positions regardless of the load added to the car after the hand brake has been set. The braking pressure manually set is transmitted to the pull rod 54 of the braking mechanism of the present invention, in the manner well known in the art.

In the case of advanced wear of the braking shoes 33, the resulting change in the linkage may be compensated for by changing the effective lengths of the push rods 38. This is accomplished by moving the pin 47 of the push rod 33 to be adjusted to the next opening 48 thereon. Although this adjustment will change the parallelism of the jointed mechanism 35, 36 and 38, the change will not be great enough toeffect, significantly, uniformity in the braking pressure of the four brake units of each car truck.

While a railway car is rolling along the tracks, the wheels 16 thereon sway by the action of their flanges against the rails, each pair of axially aligned wheels moving laterally relative to the other pairs of axially aligned wheels on the car. In the arrangement of the present invention, the brake head levers 25 on one side of the bolster 12 in each car truck are pivotally supported to move angularly with the corresponding pair of axially aligned wheels 16 in their lateral movements and independently of the brake levers on the opposite side of the bolster, when the brake is applied. By causing the brake head levers 25 to follow their corresponding wheels 16 in their lateral movements during brake application, full and even brake shoe pressure is maintained on all eight wheels of each car, in spite of the relative sway in the different pairs of aligned wheels.

In Figs. 1 to 21, the brake rotor disc 34 is shown of the type in which the heat radiating fins 68 are integral with the main body of the disc. Figs. 22 to 24 show a modified form of brake rotor disc 34 in which radiating fins 68 are separately formed from the main body of the disc as channels of U -shaped cross section and these fins are welded to the outboard face of the disc radially thereof.

In the constructions of Figs. 1 to 24, the brake rotor discs 34 and 34 are axially spaced from the rims of their corresponding car wheels 16 and are aflixed to the wheel axles 15 either directly or through the hubs of the wheels. Figs. 25 and 26 show a modified form of brake rotor disc 34*, in which the brake disc is connected directly to the corresponding car wheel 16 In this modified form, the car wheel 16 is of conventional type, except that it has integral therewith a series of ears extending radially inwardly from the inboard side of the rim of the wheel, and the brake rotor disc 34 has a rim 106 offset towards the outboard side against these ears 105 and connected thereto by fastening elements, such as bolts 107. The outboard face of the brake rotor disc 34 carries heat radiating fins 68, while the inboard face is flat to receive the braking shoe 33.

Figs. 27 and 28 show a modified form of brake rotor disc 34 in which the disc is connected directly to the corresponding car wheel 16. In this case, the wheel 16 is of conventional type, but the brake disc 34 has connected to its outer periphery a flat ring 108 by means of fastening elements such as rivets 110. The outer periphery of this ring 108 projects radially outwardly beyond the outer periphery of the brake disc 34 and is Till connected directly to the inboard side of the rim of the car wheels 16 by fastening elements, as for example studs 111. The brake disc 34 is provided on its outboard side with heat radiating fins 68 and may be provided with openings 112 near its outer periphery as a means for promoting ventilation.

Figs. 29 and 30 show still another form of brake rotor disc 34 in which the brake disc is integral with the corresponding car wheel 16 and forms a radial inward extension of the rim of said car wheel. This brake disc 34 has heat radiating fins 68 on its outboard side.

a in all forms of the invention so far described, the brake rotor disc has been a member distinct from the corresponding car wheel but made rigid therewith, either through the axle or wheel hub connection, through direct connection to the wheel by rivets, bolts or studs, or through integral formation therewith. In Figs. 31, 32 and 33 is shown still another embodiment, in which the brake rotor disc, instead of being distinct from the car wheel, forms part of the car wheel itself. In this form of the invention, the car wheel 16 may be of conventional form but the inboard side of its rim defines a brake disc 34- against which the brake shoe 33 is directly applied for braking action. In this case, the brake head lever 25 has its leg 28 shorter than in the other forms of the invention described, in order to locate the brake head 29 on said leg 28 axially opposite the brake truck 34 forming part of the car wheel 16 This brake head 29 is arcuate in shape and concentric with the car Wheel 16 and is long enough to afford the necessary braking pressure. To the brake head 2.9 is connected metal lined brake shoe 33 by means of keys 82 In the arrangement of Figs. 31 to 33, although the width of the brake shoe 33 is less than that in the constructions of Figs. 1 to 30 because of the limited brake disc area available, this is compensated for by the lengthening of the shoe and/ or by the fact that the braking pressure from the shoe is applied at a greater distance from the center of the car wheel. Also, in the design of Figs. 31 to 33, since the brake shoe 33 is comparatively narrow, it is not necessary to provide a swivel connection between the brake shoe and the brake head 29*, as in the forms of Figs. 1 to 30, to apply the braking pressure uniformly across the entire active braking area of the brake shoe, since this result is substantially accomplished by the narrowness of the brake shoe and more so as the shoe wears down.

Fig. 34 shows a modified form of linkage for operating the four brake units in each car truck. In this construction, instead of a straight brake arm 35 as in the constructions of Figs. 1 to 33, the brake arm 35 is angularly shaped to provide a branch 115, the end of which is pivotally connected to one end of the push rod 38 The other end of the push rod 38 is directly pivotally connected to a third leg extension 116 on the L-shaped brake head lever 117, so that the fulcrumed brake arm 36 in the construction of Figs. 1 to 33 is eliminated. This push rod 38 extends through the bolster 12 and obiquely thereof.

Then length of the brake arm branch 115 and the leg extension 116 of the brake head lever 117 are substantially equal, and these extend substantially at the same angle with respect to the push rod 38 therebetween; and, since the bell crank parts of the two brake head levers 25 and 117 are substantially the same, the two brake head leverwill exert equal braking pressure on the corresponding rotor discs 34. In all other respects, the construction of Fig. 34 is similar to that of Figs 1 to 21.

Figs. 35' to 38 show a modified form of beam arrangement and support for the power input to the four brake linkages 20 of Figs. 1 to 20. In this modified construction, the beam 40 is integrally formed with a pair of jawsor projections 125 in the center thereof extending obliquely upwardly and defining therebetween a socket 126 to receive therein the lower end of the inclined lever 53 A pivot pin 127, passing through these projections 123 and through the lever 53*, pivotally connects the lower end of the lever to the beam 40*. The upper end of the lever 53' is pivotally connected to a bracket 128 secured to the center sill 130 or other parts of the car body. The intermediate section of the lever 53 is pivotally secured to the pull rod 54 powered from the cylinder lever (not shown).

The lower side of the socket 126 is provided with a hole 131 to drain away moisture or water.

While the invention has been described with particular reference to specific embodiments, it is to be understood that it is not to be limited thereto, but is to be construed broadly and restricted solely by the scope of the appended claims.

What is claimed is:

1. A railway car truck comprising a pair of opposed side structures, a pair of coaxial wheels supported on said side structures respectively with their axis fixed in relation to said side structures, a pair of brake discs rigid with the wheels respectively for rotation therewith and located close to and on the inboard sides of said wheels respectively, said discs carrying respective brake surfaces on their inboard faces, a pair of L-shaped brake head levers having respective legs extending along the axis of the wheels and pivotally supported near the outer ends of said legs to said side structures respectively, the other legs of said levers extending from the inner ends of said first mentioned legs respectively along the inboard sides of said discs respectively and carrying at their free ends brake heads respectively movable towards and away from the corresponding brake faces of the brake discs into and out of braking positions as said brake head levers move about their pivot supports on said side structures, and means connecting both of said brake head levers for pivotal operations substantially in unison.

2. A railway car truck as described in claim 1 wherein the means for connecting both of said brake head levers for pivotal operations in unison comprises a bridle beam extending between said brake head levers, means for applying power to the midsection of said bridle beam to move said beam laterally, and connecting means between the ends of said bridle beam and said brake head levers respectively for moving said levers into braking positions upon application of braking power to said bridle beam through said power applying means.

3. A railway car truck comprising a pair of opposed side structures, two parallel axles extending between the side structures and supported thereon for vertical movement with said side structures, car wheels secured to the axles near the ends thereof, brake discs on the inboard sides of the wheels respectively located close to said wheels respectively and mounted rigid with said wheels for rotation therewith respectively, said discs having respective brake surfaces on their inboard faces, four L-shaped brake levers pivotally supported from the side structures, two from each structure, each of the levers having a leg extending along the axes of the wheels and pivotally supported near its outer end to the corresponding side structure, the other leg of the lever extending from the inner end of the corresponding first mentioned leg along the inboard side of the corresponding brake disc and carrying at its free end a brake head movable towards and away from the brake face of the correspond ing brake disc, as the lever is moved about its pivotal support, and means connecting all of said levers for pivotal operations substantially in unison into braking positions with respect to said discs.

4. A railway car truck comprising a pair of opposed side structures, a first pair of wheels mounted on a first axis extending between the two side structures and supported on said side structures respectively for vertical movements therewith, a second pair of wheels mounted on a second axis parallel to said first axis and supported on said side structures respectively for vertical movements therewith, a bolster located between and extending along said axes, said bolster being spring supported on said side structures, brake discs on the inboard sides of the wheels respectively located close to said wheels respectively and mounted rigid with said wheels for rotation therewith respectively, said discs having respective brake surfaces on their inboard faces, a pair of brake head levers on the side of the bolster nearest said first axis supported on said side structures respectively and carrying at their free ends brake heads movable towards and away from the inboard faces of the two discs respectively mounted rigid with the wheels of said first pair, a second pair of brake head levers on the opposite side of the bolster supported on said side structures respectively and carrying at their free ends brake heads respectively movable towards and away from the inboard faces of the other discs respectively, the sides of said bolster being separated from the sides of the wheels by spaces, each of said brake head levers being L-shaped and having one leg pivotally supported at its outer end to a corresponding one of said side structures and extending along the bolster in a corresponding one of said spaces, the other leg extending along the inboard side of the corresponding disc and carrying at its free end the corresponding brake head for coaction with the brake face of the latter disc, and means connecting all of said brake head levers for pivotal operations substantially in unison into braking positions with respect to said discs.

5. A railway car truck according to claim 4, wherein the means connecting said brake head levers for pivotal operations in unison includes a bridle beam extending between the two brake head levers on one side of the bolster, means connecting the ends of the bridle beam to the latter two brake head levers respectively, a power connection to the bridle beam to move the bridle beam and thereby to operate the latter two brake head levers substantially in unison, and means for simultaneously transmitting power from said power connection to the other two brake head levers.

6. A railway car truck, comprising a pair of opposed side structures, a pair of coaxial car wheels supported on said side structures respectively with their axis extending substantially horizontal when the truck is supported in position for operation on a horizontal road bed and fixed in relation to said side structures, a pair of brake discs on the inboard sides of said wheels rigid with the wheels respectively for rotation therewith and located close to their respective wheels, said brake discs carrying respective brake surfaces on their inboard faces extending substantially in respective vertical planes in said position of the truck, a pair of L-shaped brake head levers pivotally supported on said side structures respectively about pivot axes extending substantially vertically in said position of the truck to cause said brake head levers to move about said pivot axes respectively substantially horizontally, said brake head levers having respective legs extending along the axis of the wheel and pivotally supported on said pivot axes near their outer ends, the other legs of the brake head levers extending along the inboard sides of said discs respectively and carrying at their free ends brake heads respectively movable towards and away from the corresponding brake faces of the brake discs into and out of braking positions, a rocker for carrying a brake shoe supported on each brake head, a swivel connection between each rocker and its corresponding brake head permitting said rocker to move about a swivel axis substantially vertical in said position of the truck, and thereby to accommodate itself to the arcuate swing of the corresponding brake head lever, and to effect with substantially uniform pressure continuous surface engagement of the shoe carrying said rocker with the corresponding brake disc, and means for operating said brake head levers substantially in unison into braking position with respect to said discs.

7. A railway car truck for a car body comprising a pair of opposed side structures, a pair of coaxial car wheels supported on said side structures respectively with their axis fixed in relation to said side structures, a pair of brake discs on the inboard sides of said wheels respectively rigid with the wheels respectively for rotation therewith and located close to their respective wheels, said brake discs carrying respective brake surfaces on their inboard faces, a pair of brake head levers pivotally supported on said side structures respectively and carrying near their free ends respective brake heads movable towards and away from the corrmponding brake faces of the brake discs into and out of braking positions, the outboard sides of said discs remaining free of braking action applied directly thereto, and means connecting both of said brake head levers for pivotal operations substantially in unison into braking positions with respect to said discs, comprising a bridle beam extending between said brake head levers, a power lever one end of which is secured to the midsection of the beam and having means for connecting said power lever to a power rod operated from an air brake equipment, means supporting said power lever for vertical movement with the car body, and connecting means between the ends of said bridle beam and said brake head levers respectively for moving said levers into braking positions upon application of braking power to said bridle beam through said power lever, and including flexible connections permitting transmission of braking power to said brake head levers without transmitting the vertical movements of the car body to said brake head levers.

8. A railway car truck comprising a pair of opposed side frames extending longitudinally along the opposite sides respectively of the truck and each having a guide opening, a bolster extending between the side frames and having its ends spring-supported and guided in said openings for vertical movement, two parallel axles extending between the side frames on opposite sides of the bolster and supported on the side frames, car wheels secured to the axles near the ends thereof respectively, brake discs rigid with the wheels respectively for rotation therewith located close to said car wheels respectively on the inboard sides thereof and presenting respective brake faces on the inboard sides, four L-shaped brake head levers arranged in two sets, each set consisting of a pair of levers in opposed relationship on opposite sides of the bolster, each of the brake head levers having one leg which extends along the bolster between the bolster and the adjoining axle and which has a pivotal connection at its outer end to the adjacent side frame on one side of the guide opening for support, and having its other leg extending away from the bolster transversely of the bolster and along the inboard side of the adjoining brake head lever, the latter brake head lever leg carrying at its free end a brake head for cooperation with the brake face on the latter brake disc, the pivotal support for each brake head lever allowing the latter lever to move substantially horizontally angularly about the axis of its pivot support to move the brake head thereon towards the corresponding brake disc in braking position, and means for moving all of the brake head levers substantially simultaneously into braking positions.

9. A railway car truck as described in claim 8, wherein each of said side frames has side columns flanking its guide opening, and wherein there are provided four L-brackets connected to the side columns respectively, each of said brackets having a leg rigidly connected to the corresponding side column and extending along the corresponding side frame, and its other leg extending transversely of the corresponding side frame between the bolster and the corresponding axle, said brake head levers being pivotally connected to those legs respectively 15 of said brackets extending transversely of the side frames.

10. A railway car truck comprising a pair of opposed side structures, two parallel axles extending between said side structures with their axes substantially hori- 'zontal when the ,truck is supported in position for operation on a horizontal road bed and supported near their ends to said structures for vertical movement therewith, car wheels secured-tosaid axles near the ends thereof respectively, a bolster extending between and spring supported on said side structures and located between said axles, brake discs on the inboard sides of the wheels respectively rigid with the wheels respectively for rotation therewith and located close to their respective wheels, said brake discs carrying respective brake surfaces on their inboard faces extending sub stantially in respective vertical planes in said position of the truck, a first pair of L-shaped brake head levers on one side of the bolster for a pair of the brake discs on said side of the bolster, each of said brake levers having one leg which is loacted between the bolster and a corresponding one of said Wheels on said side of the bolster and which has its outer end pivotally supported on the corresponding side structure and on a pivot axis substantially vertical in said position on the truck, and having its other leg extending transversely of the bolster and along the inboard side of the brake disc rigid with the latter wheel, said other leg carrying at its free end a brake head, said brake head levers being supported for substantially horizontal movements about said pivot axes respectively into and out of braking positions with respect to said brake discs respectively, a rocker for carrying a brake shoe supported on each brake head, a swivel connection between each rocker and its corresponding brake head permiting said rocker to move about a swivel axis substantially vertical in said position of the truck, and thereby to accommodate itself to the arcuate swing of the corresponding brake head lever and to effect continuous surface engagement of the shoe carried by said rocker with the corresponding brake disc with substantially uniform pressure, and means for operating said levers substantially in unison into braking position with respect to said discs and comprising a bridle beam extending between the two brake head levers on one side of the bolster, means connecting the ends of the bridle beam to the latter two brake head levers respectively, a power connection to the bridle beam to move the bridle beam and thereby to operate the latter two brake head levers substantially in unison, and means for simultaneously transmitting power from said power connection to the other two. brake head levers.

References Cited in the file of this patent UNITED STATES PATENTS 1,145,416 Hirsch July 6, 1915 1,939,106 Clauser Dec. 12, 1933 2,102,222 Riley Dec. 14, 1937 2,242,853 Flowers May 20, 1941 2,274,859 Eksergian Mar. 3, 1942 2,351,573 'Ledwinka June 13, 1944 2,354,972 Baselt L Aug. 1, 1944 2,380,376 Bachman July 31, 1945 2,423,056 Tarbox June 24, 1947 2,498,625 Tack Feb. 21, 1950 2,702,102 Tack Feb. 15, 1955 FOREIGN PATENTS 298,070 Great Britain Mar. 21, 1929

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