US3857341A

US3857341A - Snubbed bolster

Info

Publication number: US3857341A
Application number: US00295871A
Authority: US
Inventors: O Neumann
Original assignee: Amsted Industries Inc
Current assignee: Amsted Industries Inc
Priority date: 1972-10-10
Filing date: 1972-10-10
Publication date: 1974-12-31
Anticipated expiration: 1991-12-31
Also published as: BR7307846D0; GB1444636A; BE805664A; JPS4971612A; ZA737432B; AU471946B2; CA969807A; AU6066273A; AR203018A1

Abstract

In a railway truck wherein friction shoes are operatively carried in wedge-shaped pockets of the bolster and are urged upwardly and outwardly by one or more control springs positioned between the bottom of the friction shoes and the tension member of the truck side frame, the invention provides for a bolster wherein the outer portion of an inclined bolster wall that extends above the plane of the bolster top wall is connected to the top wall by an integrally cast hood. Such an arrangement thereby encloses the entire bolster pocket except at the bottom of each pocket and the side of the pockets adjacent the vertical columns of the side frame. This improved construction greatly increases the strength of that portion of the inclined wall that extends to the vertical bolster side wall and above the bolster top wall.

Description

United States Patent [1 1 [111 3,857,341 Neumann Dec. 31, 1974 SNUBBED BOLSTER Primary Examiner-M. Henson Wood, Jr. [75] Inventor: Otto Walter Neumann, Chicago, Ill. Asmmm EXammer HoWard Beltran [73] Assignee: AMSTED Industries Incorporated, 57] ABSTRACT Chicago, Ill. In a railway truck wherein friction shoes are opera- [22] Flled 1972 tively carried in wedge-shaped pockets of the bolster [21 Appl. No.: 295,871 and are urged upwardly and outwardly by one or more control springs positioned between the bottom of the friction shoes and the tension member of the truck [52] Cl 105,197 IDS/202 32 side frame, the invention provides for a bolster wherein the outer portion of an inclined bolster wall g gi g g 2 that extends above the plane of the bolster top wall is le 0 earc 1 connected to the top wall by an integrally cast hood. Such an arrangement thereby encloses the entire bolster pocket except at the bottom of each pocket and [56] References Clted the side of the pockets adjacent the vertical columns UNITED STATES PATENTS of the side frame. This improved construction greatly 2,652,002 9/1953 Clasen.... 105/197 DB increases the strength of that portion of the inclined 2,661,702 12/1953 Kowalik 197 DB wall that extends to the vertical bolster side wall and 2,974,610 3/1961 Quinn et a1 105/197 DB above the bolster top wall 3,461,815 8/1969 Gedris et a1. 105/197 DB 2 Claims, 3 Drawing Figures 1 SNUBBED BOLSTER particularly to improvements in cast steel truck bolsters for such vehicles.

With the advent of larger railway vehicles and heavier loading of existing equipment, the need has arisen to structurally improve certain parts of the car truck that are subject to high stresses during actual service conditions.

One area requiring such structural improvement is the truck bolster specifically in the area on either side of the bolster where the friction shoes are positioned; as it was common in prior art arrangements for cracks to form after prolonged service in the top wall of the bolster around the inclined bolster wall that extends upwardly through the bolster top wall.

Briefly, the present invention contemplates the provision of a freight car truck comprising spaced side frames supported at their ends upon wheel and axle assemblies and interconnected by a bolster which is resiliently supported at its ends upon the side frames. The bolster is provided with shoe pockets to receive friction shoes which are urged into frictional engagement against side frame columns by compression springs to snub movements of the bolster relative to the side frames. The improved hooded construction of the bolster top wall and inclined walls prevents the cracking of the extensions of the inclined walls that was common in prior art arrangements.

The foregoing and other objects and advantages of the invention will become apparent from the following specification and the accompanying drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view of a railway truck side frame and bolster embodying a preferred form of the invention, the view being taken from the outboard side of the side frame. Portions of the side frame and bolster are broken away for clarity.

FIG. 2 is an exploded perspective view of the truck bolster friction shoes and control springs showing more clearly the improvedconstruction.

FIG. 3 is a fragmentary sectional view through the bolster structure shown in FIG. 2,. the section being taken in the vertical plane indicated by line 33.

Referring first to FIG. 1 which illustrates a portion of a truss type railway truck, the side frame indicated generally at is seen to comprise a tension member 12 and a compression member 14 interconnected by spaced vertical columns 16, the sides of which form a window 18 (FIG. 1) substantially rectangular in shape. The side frame 10 is supported in the usual manner by wheel and axle assemblies which are not shown in the drawings.

.1! should be understood that the railway truck for the purpose of the present disclosure may be considered identical at both sides thereof and for the sake of brevity only that portion shown will be described in detail.

The window 18 is adapted to receive the end of the bolster, generally indicated at 20. The lower surface 22 at the end of the bolster is supported by a plurality of support spring groups 24 which rest at their lower ends on the side frame tension member 12. In opposite side walls 26 at each end of the bolster 20 are wedgeshaped receiving pockets 28 which open outwardly toward the side frame columns 16 and have an inclined inner wall or sloped surface 30 which has a width corresponding substantially to the width of the wedgeshaped friction shoe 32 positioned therein.

The inclined inner wall 30 projects above the plane of the bolster top wall 34. That outer portion of the sloped surface 30a that extendsabove the top wall of the bolster 34 is connected to the top wall of the bolster 34 by an integrally cast hood 35. Such an arrangement encloses the entire bolster pocket 28 except at the bottom and the side adjacent the vertical column 16. This improved construction increases the strength of that portion of the inclined wall 30 that extends above the top wall 34 of the bolster 20.

One wedge-shaped friction shoe 32 is operatively carried in each pocket 28 and defines an inclined surface 36 corresponding to and frictionally engaging the inclined wall or sloped surface 30 of the pocket 28. Shoe 32 also defines a vertical surface 38 for frictionally engaging a wear plate 40 on the adjacent side frame column 16. The lower surface 42 of the wedgeshaped friction shoe 32 is engaged by the upper end of a control spring 44 which is disposed between said friction shoe 32 and the tension member 12 of the side frame 10. The inclined inner wall 30 therefore provides an inclined thrust area equal to that of the engaged portion of the inclined surface 36 of the wedge-shaped friction shoe 32. I

The improved construction of the bolster 20 greatly increases the strength of the inclined or sloped surface 30 in the bolster pocket 28, thereby eliminating the failures that were prevalent in prior art arrangements, as it was common for cracks to form at the intersection of the bolster top wall 34 and that portion of the inclined surface 30a that extends above the top wall 34 of the bolster 20. In the event the car remained in service, the upper portion of the inclined surface 30a would eventually break off, thereby allowing the friction shoe 32 to rise drastically or in some casescome out of the pocket entirely. In either case effective snubbing of the bolster is severely hampered which may result in the bolster oscillations increasing to such a magnitude that the support springs 24 would be driven to solid,- ultimately resulting in their damage.

In an effort to overcome the aforementioned problem, many arrangements were tried; most attempting to solve the problem, tried to increase the amount of metal at the intersection of the inclined surface and the top wall of the bolster; the problem, however, persisted.

The solution to the above-mentioned problem being the new and novel arrangement disclosed herein. In ar riving at this solution it was determined that the phenomenon of cracking resulted from the abrading action that the friction shoe had on the side walls just above the top wall of the bolster; specifically at the two areas located on either side of the inclined surfaces 30 and 30a where said surface joins the top wall of the bolster.

As a result of friction shoe 32 movement in the bolster pocket 28, an abrading action occurs on the inclined or sloped surface of the bolster. As a result of this abrading action, it was found that the edges on the sloped surface (notsliown), at the place of intersection with the top wall 34 of the bolster 20, become worn to a very thin edge. This resulting wear pattern eventually creates a condition of concentrated stress, the result of which causes the formation of cracks in the top wall of the bolster which extend from the intersection of the top wall of the bolster and the sloped surfaces 30 and 30a in the pocket 28. As previously mentioned, continued service ultimately results in the breaking away of thesloped surface from the bolster.

Use of the hooded arrangement hereinbefore described, prevents the undesirable build-up of stress that was common in prior art arrangements since the friction shoe can no longer wear through the top wall of the bolster at the point where the inclined surface intersects the top wall 34 of the bolster 20.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention, in the use: of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

For example, I am aware that the hooded portion over each pocket 28 could be extended across the top 34. of the bolster 20 to join the hooded portion on the opposite side of the bolster and thereby transversing the entire width of the bolster 20. Such an arrangement would greatly increase the strength of the inclined or sloped surface 30a that extends above the top wall 34 of the bolster 20.

I claim:

1. In a railway car truck bolster; the combination of top and bottom walls, spaced side walls interconnecting said top and bottom walls, said spaced side walls defining inboard and outboard sides of a friction shoe pocket, an opening in the bottom wall affording access to said pocket by an associated shoe-actuating spring, a sloping wedge wall having inboard and outboard edges, said wedge wall being integral with said side walls and integral with and extending above said top wall to afford a downwardly facing wedge surface for an associated shoe in said pocket, and a hood integral with said inboard and outboard edges of said wedge wall and with said top Wall along said edges, the outer edge of said hood being substantially coplanar with said side walls along their outer surfaces and defining therewith the outer extremity of said pocket.

2. A railway car truck bolster according to claim 1 wherein each side of the hood above the top wall is substantially triangular as seen in the end elevational view of the bolster.