Center Brace Filler And Center Plate Assembly

Abstract

A center brace filler for the center sill of a railway vehicle truck provides cross-walls which are integral with the sidewalls of the brace which lie against the walls of the center sill. The center brace is rigidly secured to the center bowl and is rigidly attached to the center sill with its upper extremities spaced from the top of the center sill.

Description

This invention relates generally to railway vehicle bogies and more particularly to a novel center brace for the center sill of the car's body bolster.

A railway vehicle body is supported by a body bolster pivotally mounted on a truck bolster. The body bolster is provided with a center sill having spaced walls which extend transversely across the bolster. These walls are supported against collapse by a center filler or center brace which is attached directly or indirectly to a center plate bowl.

Railway cars are usually built upside down and the center brace is mounted in the center sill by dropping the cast brace into place and welding, bolting or otherwise rigidly securing it to the sill. A bottom cover plate for the bolster is installed and a center plate bowl is rigidly secured thereto. It has also been proposed to provide a center brace casting having an integral center plate bowl to reduce cracking around the bowl when the car rocks from side to side. Suitable modifications must be made in the bottom cover plate to receive the integral bowl.

One of the problems encountered in mounting the center brace in the center sill has been that very close tolerances are required in making the sill and the brace in order that the center brace will fit flush with the underside of the sill. If the center brace protrudes from the sill or is too short, the center plate bowl and bottom cover "work" in the resulting space as the car rocks with the development of fatigue stresses and center plate bowl cracking.

Cracking of welds has been a problem with the heretofore available bogies. The body bolster is a beam loaded at its ends and supported at its center. As in any beam under such loading, the top cover plate of the hollow bolster is in a state of tension, the bottom cover is in compression, and the front and rear webs are in shear. Under normal symmetrical load conditions, the shear caused by the load on each side flows down to the center plate bowl without any problem. However, in an unsymmetrical condition, such as at the moment of extreme rock with the car supported only by one side bearing, the shear from the opposite end of the bolster has to flow across the ,enter center through the top and bottom covers and the center plate bowl. These are not strong or stiff in shear and tend to distort with ultimate cracking of welds on the bolster.

It is therefore an object of this invention to provide an improved center brace which will substantially reduce weld cracking. Another object of the invention is to provide a center brace which can be mounted in the center sill without problems arising from normal variation in dimensions and configuration of the center sill. A further object of the invention is to provide a center brace having the center plate bowl attached thereto and a bolster bottom cover of improved design. A still further object of the invention is to provide a center brace adapted to carry shear stiffly without significant distortion under various loading conditions. A more specific object of the invention is to provide a center brace which is not only adapted to support the walls of the center sill but also supports the center plate bowl.

Other objects will become apparent from the following description with reference to the accompanying drawing in which

FIG. 1 is a front elevation, partially in section, of a body bolster and truck bolster assembly of a railway vehicle truck;

FIG. 2 is a plan view of an embodiment of the center brace provided by this invention positioned in a center sill shown partially in section;

FIG. 3 is a section taken along the line 3--3 of FIG. 2 of the center brace assembled with the center sill, center plate bowl, sole plate and bottom cover of the body bolster;

FIG. 4 is a section taken along the line 4--4 of FIG. 3;

FIG. 5 is a plan view of another embodiment of the invention;

FIG. 6 is a section taken along the line 6--6 of FIG. 5;

FIG. 7 is a section taken along the line 7--7 of FIG. 6; and

FIG. 8 illustrates diagrammatically the relative positions of the body bolster and truck bolster at the moment of extreme rock of the car body.

The foregoing objects and others are accomplished in accordance with this invention by providing a body bolster center sill with a center brace having vertical walls spaced across the width of the bolster which extend across the center sill and are integral with vertical walls which are parallel with and lie adjacent to the sidewalls of the center sill. The vertical walls of the center brace are rigidly attached to the center plate bowl and support it as well as the vertical walls of the center sill.

The vertical walls of the center brace are shorter than the vertical walls of the center sill so they terminate near but spaced from the top wall of the center sill. The center brace and center plate bowl may be separate units rigidly secured together or may be cast as integral units but in each instance the center brace assembly rests against the foot of the center sill walls and nOt against the top wall of the sill. This enables assembly of the center brace without the problems caused by protrusion of the center brace when it is dropped into the sill. It has been found that the center brace provided by this invention supports the vertical walls of the center sill against collapse and also supports the center plate bowl when an unsymmetrical load is applied to the body bolster.

Referring now to the drawing and particularly to FIG. 1, body bolster 10 is pivotally mounted on truck bolster 11 with its center plate bowl 12 in mating engagement with center plate 13 carried by truck bolster 11. The body bolster 10 has vertically spaced top and bottom cover walls 14 and 15 and vertical front and back walls or webs 16 and 17 which combine to enclose hollow arms 18 and 19. Arms 18 and 19 are secured at their inner ends to vertical walls 20 and 21 of center sill 28. Top wall 22 is integral with vertical walls 20 and 21 which extend outwardly at their lower ends into flanges to form sill foot 23 and sill foot 24, respectively. Side bearings 25 and 26 are rigidly secured to bolster 11 at points spaced laterally from center plate 13 and limit rocking movement of car body 27.

The sidewalls 20 and 21 of center sill 28 are supported by a cast center filler or center brace 29 having a unitary structure. The embodiment of center brace 29 illustrated in FIGS. 2, 3 and 4 has the shape of a box with a substantially open top. Longitudinally spaced vertical walls 30 and 31 lie against walls 20 and 21 of center sill 28 and are integral with transversely spaced cross-walls 32 and 33. Cross-ribs 34 project upwardly into center brace 29 from bottom wall 35 and extend across from an opening 36 in bottom wall 35 to approximately the midpoint of each of walls 30, 31, 32 and 33. The cross-ribs 34 which extend to walls 30 and 31 are integral with vertical ribs 37 and 38 which extend vertically along walls 30 and 31, respectively. Bottom wall 35 is substantially flat adjacent each of the vertical walls 30, 31, 32 and 33 but has a substantially cylindrical protuberance or boss 39 provided with opening 36 for the king pin. As illustrated in FIG. 3, walls 30 and 31 and ribs 37 and 38 are shorter than walls 32 and 33 but join therewith at the corners to form inwardly projecting tabs which serve as a top for corner posts 40.

Sole plate 41 has an opening which fits loosely about cylindrical protuberance 39 and lies against the external surface of bottom wall 35 and against foot 23 and foot 24. Sole plate 41 is oF substantially the Same width as bolster 10 and extends to approximately the middle of foot 23 and foot 24. Bottom cover 15 is welded to the undersides of feet 23 and 24.

A torroid or donut-shaped center plate bowl 12 is fitted snugly around the cylindrical protruding member 39. Center plate bowl 12 has a centrally disposed opening to receive member 39 and has four peripherally spaced radial ribs which divide it into four equally dimensioned compartments.

Installation of the embodiment of center brace 29 shown in FIGS. 2, 3 and 4 is simple. The one-piece cast brace 29 is assembled with sole plate 41 and center bowl 12 as illustrated in FIGS. 3 and 4. An annular weld along chamfered wall 43 fixedly secures the three elements together. The assembly is dropped into center sill 28. Sole plate 41 comes to rest on sill feet 23 and 24 with tabs 40 near but spaced from top 22 of center sill 28. Sole plate 41 is clamped to sill feet 23 and 24 and welded thereto. If desired, center bowl 42 may also be welded around its periphery to the sole plate 41. The center brace 29 may then be welded to the center sill 28 through welding slots 43 in vertical walls 20 and 21.

The embodiment of center brace 29' illustrated in FIGS. 5, 6 and 7 is also a cast single unit and is shown with integral rear draft stops 42 and extension 44 for attachment purposes, both of conventional configuration. Such draft stops 43 and attachment 44 may also be cast along with the center brace 29 of FIGS. 2, 3 and 4, if desired. The center bowl 12' of the embodiment of FIGS. 5, 6 and 7 is integral with walls 30', 31', 32', and 33'. As shown in FIG. 7, a shoulder 45 around the periphery of the upper edge of center bowl 12' fits against the undersides of feet 23 and 24 of center sill 28 and is fixedly secured by welding thereto. Bottom cover 15 is also welded to feet 23 and 24.

In the embodiment illustrated in FIGS. 5, 6 and 7, cross-ribs 34' join walls 32' and 33' near the corners where walls 32' and 33' join walls 30' and 31'.

Roll conditions on a railway car body bolster 10 are illustrated diagrammatically in FIG. 8. The car body has rocked to the left and is about to rock back to the right. At this point all weight is on the left side bearing 25. The weight from the right side sill 46 comes towards the left as shear in bolster webs 16 and 17. To reach the support point it must cross the center area of the bolster 10 through available metal. If center brace 29 is of conventional construction without cross-walls similar to 32 and 33 of FIG. 4, only the top and bottom cover plates 14 and 15 are available. These plates are relatively flexible and tend to bend into S-shapes, with very high stresses at the corners and welds. Cross-walls 32 and 33 provide additional metal to carry the weight from right to left through center sill 29 without bending and the development of high stresses at the corners and welds.

The sole plate 41 of the embodiment of FIGS. 2, 3 and 4 may terminate near the middle of feet 23 and 24 as illustrated or it may extend outwardly beyond the feet. Bottom cover plate 15 may be butted against the end of sole plate 41 or it may lie over the end of the plate 15 and be welded thereto. The center brace may be welded to the sill walls through the welding slots 47 in sill walls 30 and 31 as described above or it may be welded adjacent the four upper corners 40 to the sill walls. The embodiment having the searate center plate bowl attached to the center brace as illustrated in FIGS. 3 has the advantage that worn or cracked bowls can be replaced without replacing the center brace. It also enables one to make the bowl of wear resistant material without requiring the whole unit be made of the same material. For example, the center brace may be cast Grade "B" steel and the center bowl forged steel or Grade "C" cast steel.

Although the invention has been described in detail for the purposes of illustration, it is to be understood that such detail is solely for that purpose and that those skilled in the art can make modifications therein without departing from the spirit and scope of the invention except as it may be limited by the claims.

Claims

The embodiments Of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A center brace for the center sill of a railway vehicle and a body bolster center bearing assembly, said center sill having sidewalls, a closed top and open bottom, each of said sidewalls carrying an external sill foot, said center brace having substantially rectangular box-like shape with an open top, a base and four integral upstanding sidewalls with a first pair thereof adapted to be disposed against the sidewalls of the center sill while each of the second pair spans the space between the sidewalls of the center sill, said base carrying a centrally disposed outwardly projecting boss having an opening therethrough for a kingpin, a sole plate about said boss and against said bottom wall end sill feet, a ring about the boss with one face against the sole plate and the other face substantially flush with the closed end of the boss, and means for securing the ring to the boss and thereby secure the sole plate against the sill feet of the center sill, said ring and the portion of the boss enclosed thereby forming a center bearing adapted to mate with a center bearing of a truck bolster.

2. The assembly of claim 1 wherein the center brace is a one piece casting, the sole plate is welded to each sill foot, said sill sidewalls have slots therein and are welded to the adjacent sidewalls of the center brace and the said ring is welded to the boss.

3. A center filler and center plate assembly for a railway vehicle comprising a center filler having a pair of walls adapted to be disposed adjacent to the walls of a center sill having sill feet, and a bottom wall having a centrally disposed depending boss, an opening through the boss to receive a king pin, a sole plate about the boss and disposed against the said bottom wall and adapted to engage the sill feet, and a ring secured about the boss with one face against the sole plate and the other face substantially flush with the external surface of the boss, said ring and boss combining to form a bolster center plate adapted to mate with a center bowl of a railway truck.