Title:
TRUCK CENTER PLATE BEARING
United States Patent 3847090
Abstract:
A bolster and car center plate assembly having complimentary load-bearing surfaces with spaced outer portions, thus shifting the loading toward the central portions and preventing failure at the outer portions as the car rocks during normal operation.
Inventors:
Love, Robert B. (Park Forest, IL)
Radwill, Robert P. (Oak Lawn, IL)
Radwill, Robert P. (Oak Lawn, IL)
Application Number:
05/339586
Publication Date:
11/12/1974
Filing Date:
03/09/1973
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Export Citation:
Assignee:
Amsted Industries Incorporated (Chicago, IL)
Primary Class:
Other Classes:
105/226
International Classes:
B61F5/16; B61F5/02; F16C17/04; B61F5/50; B61F5/16
Field of Search:
105/199C,199CB,226 267/3 308/137,138
Primary Examiner:
Wood Jr., Henson M.
Assistant Examiner:
Beltran, Howard
Attorney, Agent or Firm:
Schlegel Jr., Walter L.
Claims:
What is claimed is
1. A center plate assembly for a railway vehicle comprising; a body center plate having a body central portion including a lower frusto-conical surface tapering inwardly from its outer edge toward said body central portion, and a truck center plate having a truck central portion including an upper frusto-conical surface tapering inwardly from its outer edge toward said truck central portion, said frusto-conical surfaces being complementary and forming load-bearing surfaces between said plates; at least one of said frusto-conical surfaces having a circumferentially oriented depressed contour contiguous to at least part of the outer edge of that surface.
2. A center plate assembly as set forth in claim 1 wherein said frusto-conical surfaces have circumferentially oriented depressed contours contiguous to at least part of their outer edges, thereby providing spacing of said surfaces from each other.
3. A bolster assembly for a railway vehicle comprising; a bolster having a longitudinal axis, a truck center plate on said bolster having an upper surface and an end surface; a body center plate having a lower surface which is complementary to said upper surface and is engagable therewith forming load bearing surfaces between said plates; said truck center plate also having a circumferentially oriented depressed contour intermediate said upper surface and said end surface.
4. A bolster assembly as set forth in claim 3 wherein said contour is concave when viewed in vertical cross-section.
5. A bolster assembly as set forth in claim 4 wherein said truck center plate has a concave contour on opposite sides of said center plate and each concave contour is transverse to said longitudinal axis.
6. A bolster assembly as set forth in claim 4 wherein the intersection of said concave contour with said upper surface defines an inner contact line, and the intersection of said concave contour with said end surface defines an outer contact line.
1. A center plate assembly for a railway vehicle comprising; a body center plate having a body central portion including a lower frusto-conical surface tapering inwardly from its outer edge toward said body central portion, and a truck center plate having a truck central portion including an upper frusto-conical surface tapering inwardly from its outer edge toward said truck central portion, said frusto-conical surfaces being complementary and forming load-bearing surfaces between said plates; at least one of said frusto-conical surfaces having a circumferentially oriented depressed contour contiguous to at least part of the outer edge of that surface.
2. A center plate assembly as set forth in claim 1 wherein said frusto-conical surfaces have circumferentially oriented depressed contours contiguous to at least part of their outer edges, thereby providing spacing of said surfaces from each other.
3. A bolster assembly for a railway vehicle comprising; a bolster having a longitudinal axis, a truck center plate on said bolster having an upper surface and an end surface; a body center plate having a lower surface which is complementary to said upper surface and is engagable therewith forming load bearing surfaces between said plates; said truck center plate also having a circumferentially oriented depressed contour intermediate said upper surface and said end surface.
4. A bolster assembly as set forth in claim 3 wherein said contour is concave when viewed in vertical cross-section.
5. A bolster assembly as set forth in claim 4 wherein said truck center plate has a concave contour on opposite sides of said center plate and each concave contour is transverse to said longitudinal axis.
6. A bolster assembly as set forth in claim 4 wherein the intersection of said concave contour with said upper surface defines an inner contact line, and the intersection of said concave contour with said end surface defines an outer contact line.
Description:
The present invention relates generally to the underframe construction of a railway car vehicle and its supporting structure. More particularly, the invention relates to improved construction for a center plate assembly.
The prior art includes a large number of center plate assembly designs. These generally include a body center plate depending from the underside of a railway car body. The body center plate is supported by a complimentary bolster center plate upstanding from the bolster of an associated railway truck. Early designs of such assemblies had generally horizontal mating surfaces between the body and truck center plates. A departure from conventional body and truck centerplates involves the use of frusto-conical mating surfaces for accomodation of the body center plate by the bolster center plate.
Experience has taught that high compressive stresses appear at the edges of the frusto-conical center plates as the car body rocks during normal railway operation. Attempts to alleviate these stresses by enlarging or otherwise modifying the fillet which blends a bolster center plate assembly into the top member of its bolster have been only partially successful. Stresses on 100 ton cars approach yield at an applied load as low as 100,000 lbs. Ideally, stresses in this area should be below yield at an applied load of at least 170,000 lbs.
An object of the present invention is to provide a center plate assembly designed to move the loading away from the highly stressed areas at the edge of the center plate assembly to an area where such loading is accomodated without difficulty.
A further object of the invention is to provide a center plate assembly construction having all or a portion of its outer area cut away so as to restrict loading to the central area thereof.
Other objects and features of the invention will be apparent to those skilled in the art upon consideration of the disclosure herein in conjunction with the drawings in which:
FIG. 1 is a fractional side-elevational view of a railway truck bolster having a frusto-conical center plate assembly in conjunction with a complimentary railway car body center plate assembly;
FIG. 2 is a fractional plan view of the bolster center plate assembly shown in FIG. 1; and
FIG. 3 is a detailed side-elevational view taken along the Lines 3--3 of FIG. 2 showing details of the improved bolster center plate assembly.
The invention is directed to the center plate assembly of a railway truck bolster and its associated railway car body bolster. The railway car is supported by the truck bolster for movement relative thereto about the vertical axis of a center plate. The railway car is further disposed for relative rocking movement relative to the associated bolster.
Turning now more particularly to the drawings, the invention includes a truck bolster 10 having a longitudinal axis and being resiliently supported at its ends by conventional side frames and wheel assemblies (not shown). Bolster 10 includes an upstanding bolster center plate assembly 12 having an upwardly facing frusto-conical load bearing surface 14. Bolster center plate 12 defines king pin opening 16 for accommodating a king pin (not shown), about which surface 14 extends. At the outer rim of surface 14, bolster center plate 12 defines a downwardly facing end surface 18 having a fillet 20 merging into the top of bolster 10.
A car center plate assembly 22 extends downwardly from an associated railway car body (not shown) and defines a frusto-conical load bearing surface 24 complimentary with surface 14 of bolster center plate 12. Car center plate 22 further defines a king pin opening 26. King pin openings 16 and 26 are in substantial vertical alignment to accommodate a king pin.
As the car body rotates relative to the truck bolster, the load is sustained by load bearing surfaces 14 and 24. As the car body rocks during normal railway operation, the uniform load sustained by load bearing surface 14 in the normal assembly position is transferred to the adjacent end surface 18. This load concentration substantially increases the stress, resulting in possible failure in that area or in the adjacent area of the bolster.
In order to prevent this failure, our load bearing surface 14 of bolster center plate 12 defines a novel contour. This contour results from cutting away a portion of load bearing surface 14 to define a depressed contour surface 28 extending transversely across the longitudinal axis of bolster 10 adjacent end surface 18. This contour surface 28 prevents the load from being applied at the end portions of load bearing surface 14 as the railway car body rocks, and thereby restricts high stress magnitudes under adverse car rock.
In a preferred form of the invention, contour surface 28 extends transversely approximately four inches on either side of the longitudinal axis of truck bolster 10 and a distance of approximately 1 1/4 inches along its longitudinal axis between an inner contact line 30 and an outer contact line 32. The depression of contour surface 28 should, of course, be sufficient to provide relief as the railway car body rocks relative thereto. In our preferred form of this invention, it has been shown that a depression of 1/4 inch is adequate for this purpose, depending upon the extent of wear allowance.
It should be emphasized that the depressed contour provides stress relief not only at and adjacent to end surface 18 of bolster center plate 12, but also shifts the load away from this end surface so that it may be accommodated more evenly throughout load bearing surface 14.
Although the preferred form of the invention shows the novel contour in the truck center plate, it should be understood that the contour may be provided in the body center plate or in a combination of both body and truck center plate assemblies.
While the invention has been described with regard to one type of body center plate assembly and one type of truck center plate assembly, it should be understood that modifications may be made in these elements as well as changes in the overall design. For example, the frusto-conical surfaces may taper downwardly rather than upwardly, as shown in the drawings, without departing from the spirit of this invention, which is to be limited only by the claims herein.
The prior art includes a large number of center plate assembly designs. These generally include a body center plate depending from the underside of a railway car body. The body center plate is supported by a complimentary bolster center plate upstanding from the bolster of an associated railway truck. Early designs of such assemblies had generally horizontal mating surfaces between the body and truck center plates. A departure from conventional body and truck centerplates involves the use of frusto-conical mating surfaces for accomodation of the body center plate by the bolster center plate.
Experience has taught that high compressive stresses appear at the edges of the frusto-conical center plates as the car body rocks during normal railway operation. Attempts to alleviate these stresses by enlarging or otherwise modifying the fillet which blends a bolster center plate assembly into the top member of its bolster have been only partially successful. Stresses on 100 ton cars approach yield at an applied load as low as 100,000 lbs. Ideally, stresses in this area should be below yield at an applied load of at least 170,000 lbs.
An object of the present invention is to provide a center plate assembly designed to move the loading away from the highly stressed areas at the edge of the center plate assembly to an area where such loading is accomodated without difficulty.
A further object of the invention is to provide a center plate assembly construction having all or a portion of its outer area cut away so as to restrict loading to the central area thereof.
Other objects and features of the invention will be apparent to those skilled in the art upon consideration of the disclosure herein in conjunction with the drawings in which:
FIG. 1 is a fractional side-elevational view of a railway truck bolster having a frusto-conical center plate assembly in conjunction with a complimentary railway car body center plate assembly;
FIG. 2 is a fractional plan view of the bolster center plate assembly shown in FIG. 1; and
FIG. 3 is a detailed side-elevational view taken along the Lines 3--3 of FIG. 2 showing details of the improved bolster center plate assembly.
The invention is directed to the center plate assembly of a railway truck bolster and its associated railway car body bolster. The railway car is supported by the truck bolster for movement relative thereto about the vertical axis of a center plate. The railway car is further disposed for relative rocking movement relative to the associated bolster.
Turning now more particularly to the drawings, the invention includes a truck bolster 10 having a longitudinal axis and being resiliently supported at its ends by conventional side frames and wheel assemblies (not shown). Bolster 10 includes an upstanding bolster center plate assembly 12 having an upwardly facing frusto-conical load bearing surface 14. Bolster center plate 12 defines king pin opening 16 for accommodating a king pin (not shown), about which surface 14 extends. At the outer rim of surface 14, bolster center plate 12 defines a downwardly facing end surface 18 having a fillet 20 merging into the top of bolster 10.
A car center plate assembly 22 extends downwardly from an associated railway car body (not shown) and defines a frusto-conical load bearing surface 24 complimentary with surface 14 of bolster center plate 12. Car center plate 22 further defines a king pin opening 26. King pin openings 16 and 26 are in substantial vertical alignment to accommodate a king pin.
As the car body rotates relative to the truck bolster, the load is sustained by load bearing surfaces 14 and 24. As the car body rocks during normal railway operation, the uniform load sustained by load bearing surface 14 in the normal assembly position is transferred to the adjacent end surface 18. This load concentration substantially increases the stress, resulting in possible failure in that area or in the adjacent area of the bolster.
In order to prevent this failure, our load bearing surface 14 of bolster center plate 12 defines a novel contour. This contour results from cutting away a portion of load bearing surface 14 to define a depressed contour surface 28 extending transversely across the longitudinal axis of bolster 10 adjacent end surface 18. This contour surface 28 prevents the load from being applied at the end portions of load bearing surface 14 as the railway car body rocks, and thereby restricts high stress magnitudes under adverse car rock.
In a preferred form of the invention, contour surface 28 extends transversely approximately four inches on either side of the longitudinal axis of truck bolster 10 and a distance of approximately 1 1/4 inches along its longitudinal axis between an inner contact line 30 and an outer contact line 32. The depression of contour surface 28 should, of course, be sufficient to provide relief as the railway car body rocks relative thereto. In our preferred form of this invention, it has been shown that a depression of 1/4 inch is adequate for this purpose, depending upon the extent of wear allowance.
It should be emphasized that the depressed contour provides stress relief not only at and adjacent to end surface 18 of bolster center plate 12, but also shifts the load away from this end surface so that it may be accommodated more evenly throughout load bearing surface 14.
Although the preferred form of the invention shows the novel contour in the truck center plate, it should be understood that the contour may be provided in the body center plate or in a combination of both body and truck center plate assemblies.
While the invention has been described with regard to one type of body center plate assembly and one type of truck center plate assembly, it should be understood that modifications may be made in these elements as well as changes in the overall design. For example, the frusto-conical surfaces may taper downwardly rather than upwardly, as shown in the drawings, without departing from the spirit of this invention, which is to be limited only by the claims herein.