RAILCAR COVER PLATE
A metal cover plate includes a first section and a second section. The first section includes a first end and an outer perimeter. The outer perimeter includes a termination end. The termination end is generally opposite the first end. The first section defines a hole. The second section includes a first end and an outer perimeter. The second section is coupled at the first end of the second section to the first end of the first section and extends from the first end of the first section in a direction generally opposite the termination end of the first section. The metal cover plate is welded to a railcar along the outer perimeter of the first section and the outer perimeter of the second section.
This application claims priority to U.S. Provisional Application Ser. No. 62/861,558 entitled “RAILCAR COVER PLATE,” filed Jun. 14, 2019, the entire content of which is incorporated herein by reference.
TECHNICAL FIELDThis disclosure relates generally to railroad cars and more specifically to reinforcement cover plates welded on to railroad cars.
BACKGROUNDRailroad cars experience a variety of different stresses during operation. To prevent these stresses from damaging the railroad cars, reinforcement cover plates are often added to the structure of the cars.
SUMMARYRailroad cars experience a variety of different stresses during operation. To prevent these stresses from damaging the railroad cars, reinforcement cover plates are often added to the structure of the cars. For example, a reinforcement plate may be welded to the flange of a beam within the railroad car, or a reinforcement plate may be welded on to a second plate of the railroad car. Inevitably, each reinforcement plate will terminate at some point along the beam or the second plate onto which it is welded. Any stress that is carried by the cover plate must then exit the cover plate at this termination point. As a result, cover plates experience a large concentration of stress at their termination points, which can often result in fatigue cracking at the toe of the weld along the termination point, where the stress exits the cover plate into the beam or the second plate onto which the cover plate is welded. Consequently, railroad car manufacturers often thicken the plates onto which reinforcement plates are attached, to reduce the operational stress levels in these plates and thereby help avoid fatigue cracking. However, thickening the plates onto which cover plates are attached adds significant weight to the railroad cars, which may reduce their fuel efficiency and load capacity.
This disclosure contemplates an unconventional reinforcing cover plate that addresses one or more of the above issues. In certain embodiments, a hole is placed within a tapered end of the cover plate. When the cover plate is welded on to a beam or other plate and stress is applied to the plate, a portion of the stress is unable to pass beyond the hole and into the end of the cover plate. Consequently, this stress does not exit the plate through the portion of the weld along the termination point of the cover plate. Rather, it is forced to exit the cover plate along the remainder of the weld (e.g., along the taper of the cover plate). In this manner, certain embodiments reduce the stress per unit length that exits through the weld, thereby preventing fatigue cracking of the weld. Certain embodiments of the railcar cover plate are described below.
According to one embodiment, a metal cover plate includes a first section and a second section. The first section includes a first end and an outer perimeter. The outer perimeter includes a termination end. The termination end is generally opposite the first end. The first section defines a hole. The second section includes a first end and an outer perimeter. The second section is coupled at the first end of the second section to the first end of the first section and extends from the first end of the first section in a direction generally opposite the termination end of the first section. The metal cover plate is welded to a railcar along the outer perimeter of the first section and the outer perimeter of the second section.
According to another embodiment, a method includes forming a metal cover plate. The metal cover plate includes a first section and a second section. The first section includes a first end and an outer perimeter. The outer perimeter includes a termination end. The termination end is generally opposite the first end. The first section defines a hole. The second section includes a first end and an outer perimeter. The second section is coupled at the first end of the second section to the first end of the first section and extends from the first end of the first section in a direction generally opposite the termination end of the first section. The method also includes welding the metal cover plate to a railcar along the outer perimeter of the first section and the outer perimeter of the second section.
According to a further embodiment, a railcar includes a side sill and a metal cover plate. The metal cover plate includes a first section and a second section. The first section includes a first end and an outer perimeter. The outer perimeter includes a termination end. The termination end is generally opposite the first end. The first section defines a hole. The second section includes a first end and an outer perimeter. The second section is coupled at the first end of the second section to the first end of the first section and extends from the first end of the first section in a direction generally opposite the termination end of the first section. The metal cover plate is welded to the side sill along the outer perimeter of the first section and the outer perimeter of the second section.
Certain embodiments provide one or more technical advantages. For example, an embodiment prevents fatigue cracking in welds around reinforcement plates. As another example, an embodiment improves the fatigue life of a welded cover plate termination by at least a factor of two. As a further example, an embodiment improves the fuel efficiency of railroad cars and/or the load capacity of railroad cars by reducing the weight of reinforcement plates used on the railroad cars. Certain embodiments may include none, some, or all of the above technical advantages. One or more other technical advantages may be readily apparent to one skilled in the art from the figures, descriptions, and claims included herein.
For a more complete understanding of the present disclosure, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
Embodiments of the present disclosure and its advantages are best understood by referring to
Railroad cars experience a variety of different stresses during operation. To prevent these stresses from damaging the railroad cars, reinforcement plates are often added to the structure of the cars. For example, a reinforcement plate may be welded to the flange of a beam within the railroad car, or a reinforcement plate may be welded on to a second plate of the railroad car. Inevitably, each reinforcement plate will terminate at some point along the beam or the second plate onto which it is welded. Any stress that is carried by the cover plate must then exit the cover plate at this termination point. As a result, cover plates experience a large concentration of stress at their termination points, which can often result in fatigue cracking at the toe of the weld along the termination point, where the stress exits the cover plate. Consequently, manufacturers often thicken the reinforcement plates that they use on railroad cars, to reduce the operational stress levels in the plates and thereby help avoid fatigue cracking. However, thickening the reinforcement plates adds significant weight to the railroad cars, which may reduce their fuel efficiency and load capacity.
This disclosure contemplates an unconventional reinforcing cover plate that addresses one or more of the above issues. In certain embodiments, a hole is placed within a tapered end of the cover plate. When the cover plate is welded on to a beam or other plate and stress is applied to the plate, a portion of the stress is unable to pass beyond the hole and into the end of the cover plate. Consequently, this stress does not exit the plate through the portion of the weld along the termination point of the cover plate. Rather, it is forced to exit the cover plate along the remainder of the weld, along the taper of the cover plate. In this manner, certain embodiments reduce the stress per unit length that exits through the weld, thereby preventing fatigue cracking of the weld. The improved cover plate will be described in more detail using
Numerous attempts have been made to construct cover plates that, when welded to a beam or other metal surface, do not experience fatigue cracks in the welds. For example,
In order to prevent fatigue cracks from developing in cover plate 105, it may be desirable to remove a portion of the stress traveling through cover plate 105, before this stress reaches termination location 110 and travels through termination weld 120. On the other hand, in order for cover plates 105 to achieve their desired purpose of reinforcing portions of a railcar structure that are subject to high levels of stress, it is desirable to maintain the full level of stress along a majority of the length of cover plates 105 up until a location quite near termination location 110.
While such devices work well for vertically connected cover plates, they are not suitable for the terminations of flat plates connected to the surface of a beam or other piece of metal, where the heights of the plates are significantly smaller than the width of the plates. Given that such horizontal plates are commonly used to provide reinforcement for the structural beams and other structural components of railcars, this disclosure contemplates a new method of improving the fatigue life of horizontal cover plates, such as those typically used in the railroad industry.
Cover plate 200A includes first section 202, second section 204, and hole 206, located near termination end 224 of first section 202. This disclosure contemplates that second section 204 may be of any suitable geometry. For example, in certain embodiments, and as illustrated in
First section 202 includes first end 218, termination end 224, third edge 220, fourth edge 222, and hole 206. First section 202 is coupled to first end 214 of second section 204 at first end 218. First end 218 may be generally located opposite termination end 224, such that the distance between first end 218 and termination end 224 defines the length of first section 202. Similarly, third edge 220 may be generally located opposite fourth edge 222, such that the distance between third edge 220 and fourth edge 222 defines the width of first section 202. Third edge 220 connects a top of first end 218 to a top of termination end 224. Fourth edge 222 connects a bottom of first end 218 to a bottom end of termination end 224, such that first end 218, termination end 224, third edge 220, and fourth edge 222 define the perimeter of first section 202. While first end 218, third edge 220, and fourth edge 222 are depicted in
Hole 206 is located inside first section 202 such that hole 206 is surrounded by the metal of first section 202 at all points along the perimeter 208 of hole 206. Hole 206 is positioned within first section 202 such that the center of hole 206 is located closer to termination end 224 than to first end 218. While hole 206 is depicted in
Cover plate 200A is welded to a beam or piece of metal along the outer perimeter of cover plate 200A, to provide reinforcement to the beam or piece of metal. Here, the outer perimeter of cover plate 200A includes termination end 224, first edge 210, second edge 212, third edge 220, and fourth edge 222. In certain embodiments, the outer perimeter of cover plate 200A may also include second end 216. In embodiments in which second section 204 is coupled to an additional section at second end 216, the outer perimeter of cover plate 200A includes termination end 224, first edge 210, second edge 212, third edge 220, fourth edge 222, and the outer perimeter of the additional section. Cover plate 200A is not welded to the beam or piece of metal along inner perimeter 208 of hole 206. In this manner, in certain embodiments, when stress is applied to cover plate 200A, a portion of the stress is unable to travel through hole 206 and into portions of first section 202 beyond hole 206. Thus, this portion of stress does not exit cover plate 200A through the weld along termination edge 224. Instead, in such embodiments, this portion of stress is forced to exit cover plate 200A through the welds along other portions of cover plate 200A. For example, the portion of stress may exit cover plate 200A through the weld along third edge 220 and fourth edge 222. Decreasing the total amount of stress exiting cover plate 200A through the weld along termination end 224 improves the fatigue life of cover plate 200A, reducing the likelihood that fatigue cracks will develop in the weld along termination end 224.
In certain embodiments, a flexible seal is provided along the perimeter 208 of hole 206 to seal the space between cover plate 200A and the beam or piece of metal onto which it is welded from the elements, while nevertheless ensuring that the perimeter 208 of hole 206 is not rigidly connected to the beam or piece of metal onto which cover plate 200A is welded. For example, in certain embodiments, caulking is applied to the perimeter 208 of hole 206.
This disclosure contemplates that the size, position, and shape of hole 206 may be chosen to maximize the portion of stress which is unable to pass through hole 206 into termination end 224. For example, manufacturing cover plate 200A may include forming a variety of cover plates, differing only in the size, position, and/or shape of hole 206, applying stress to the cover plates, measuring the stress at the termination end of the cover plates, and choosing the size, position, and shape of hole 206 that results in the least amount of stress at termination end 224.
While
Fourth section 228 includes third end 232, and rounded termination end 224. Fourth section 228 is coupled to second end 230 of third section 226 along third end 232. In certain embodiments, hole 206 is contained entirely within third section 226. In other embodiments, hole 206 is contained entirely within fourth section 228. In further embodiments, a portion 234 of hole 206 is contained within fourth section 228, while the remainder of hole 206 is contained within third section 226.
In certain embodiments, cover plate 200B is welded to a beam or other piece of metal along first edge 210, second edge 212, third edge 220, fourth edge 222, and rounded termination end 224. In embodiments in which second end 216 is a termination end, cover plate 200B is additionally welded to the beam or other piece of metal along second end 216. In embodiments in which second section 204 is coupled to an additional section along second end 216 of second section 204, cover plate 200B is additionally welded to the beam or other piece of metal along the outer perimeter of the additional section. In certain such embodiments, when stress is applied to cover plate 200B, a portion of the stress is unable to travel through hole 206 and into fourth section 228, beyond hole 206. Thus, this portion of stress does not exit cover plate 200B through the weld along termination edge 224. Instead, in such embodiments, this portion of the stress is forced to exit cover plate 200B through the welds along the tapered edges 220 and 222 of third section 226. In this manner, certain embodiments of cover plate 200B improve the fatigue life of the weld along termination end 224.
By inserting holes 325 into reinforcement plate 335, in certain embodiments, a thinner side sill plate 315 may be used in well car 300 than in conventional well cars, in which railroad car manufacturers often thicken the plates onto which reinforcement plates are attached to reduce the operation stress levels in the plates and thereby help avoid fatigue cracking. Adding holes 325 reduces the amount of stress that exits reinforcement plate 335 into side sill 315 at the termination locations of the plate, thereby improving the fatigue life of the termination location weld without adding additional weight to the well car structure. Accordingly, in certain embodiments, improved cover plates 335 reduce the empty weight of railcars and/or increase the fuel efficiency of the cars.
Modifications, additions, or omissions may be made to method 500 depicted in
Although the present disclosure includes several embodiments, a myriad of changes, variations, alterations, transformations, and modifications may be suggested to one skilled in the art, and it is intended that the present disclosure encompass such changes, variations, alterations, transformations, and modifications as falling within the scope of the appended claims.
Claims
1. A system comprising:
- a railcar; and
- a metal cover plate welded to the railcar, the metal cover plate comprising: a first section comprising a first end and an outer perimeter, the outer perimeter comprising a termination end, wherein: the termination end is generally opposite the first end; and the first section defines a hole; and a second section comprising a first end and an outer perimeter, the second section is coupled at the first end of the second section to the first end of the first section and extends from the first end of the first section in a direction generally opposite the termination end of the first section, the metal cover plate is welded to the railcar along the outer perimeter of the first section and the outer perimeter of the second section.
2. The system of claim 1, wherein a perimeter of the hole is curved in shape.
3. The system of claim 2, wherein the hole is circular in shape.
4. The system of claim 1, wherein the first section comprises:
- a third section comprising the first end, a second end, and a taper, the second end generally opposite the first end, the taper between the first end and the second end; and
- a fourth section comprising a third end and the termination end, the fourth section coupled at the third end of the forth section to the second end of the third section and extending from the second end of the third section in a direction generally opposite the first end of the third section, the termination end comprising a rounded termination.
5. The system of claim 4, wherein a portion of the hole is located within the fourth section.
6. The system of claim 1, wherein a thickness of the metal cover plate is less than a length measured from the first end of the first section to the termination end of the first section.
7. The system of claim 1, wherein a flexible seal is provided around the perimeter of the hole.
8. A method comprising:
- forming a metal cover plate comprising: a first section comprising a first end and an outer perimeter, the outer perimeter comprising a termination end, wherein: the termination end is generally opposite the first end; and the first section defines a hole; and a second section comprising a first end and an outer perimeter, the second section is coupled at the first end of the second section to the first end of the first section and extends from the first end of the first section in a direction generally opposite the termination end of the first section; and
- welding the metal cover plate to a railcar along the outer perimeter of the first section and the outer perimeter of the second section.
9. The method of claim 8, wherein a perimeter of the hole is curved in shape.
10. The method of claim 9, wherein the hole is circular in shape.
11. The method of claim 8, wherein the first section comprises:
- a third section comprising the first end, a second end, and a taper, the second end generally opposite the first end, the taper between the first end and the second end; and
- a fourth section comprising a third end and the termination end, the fourth section coupled at the third end of the forth section to the second end of the third section and extending from the second end of the third section in a direction generally opposite the first end of the third section, the termination end comprising a rounded termination.
12. The method of claim 11, wherein a portion of the hole is located within the fourth section.
13. The method of claim 8, wherein a thickness of the metal cover plate is less than a length measured from the first end of the first section to the termination end of the first section.
14. The method of claim 8, further comprising applying caulking around the perimeter of the hole.
15. A railcar comprising:
- a side sill; and
- a metal cover plate comprising: a first section comprising a first end and an outer perimeter, the outer perimeter comprising a termination end, wherein: the termination end is generally opposite the first end; and the first section defines a hole; and a second section comprising a first end and an outer perimeter, the second section is coupled at the first end of the second section to the first end of the first section and extends from the first end of the first section in a direction generally opposite the termination end of the first section, the metal cover plate is welded to the side sill along the outer perimeter of the first section and the outer perimeter of the second section.
16. The railcar of claim 15, wherein a perimeter of the hole is curved in shape.
17. The railcar of claim 15, wherein the first section comprises:
- a third section comprising the first end, a second end, and a taper, the second end generally opposite the first end, the taper between the first end and the second end; and
- a fourth section comprising a third end and the termination end, the fourth section coupled at the third end of the forth section to the second end of the third section and extending from the second end of the third section in a direction generally opposite the first end of the third section, the termination end comprising a rounded termination.
18. The railcar of claim 17, wherein a portion of the hole is located within the fourth section.
19. The railcar of claim 15, wherein a thickness of the metal cover plate is less than a length measured from the first end of the first section to the termination end of the first section.
20. The railcar of claim 15, wherein a flexible seal is provided around the perimeter of the hole.
Type: Application
Filed: May 18, 2020
Publication Date: Dec 17, 2020
Inventor: Shaun Richmond (Frankfort, IL)
Application Number: 16/876,469