The present application relates to multi-unit railroad freight cars, and in particular to the attachment of inter-unit articulated connectors to center sills of car units.
Multi-unit railroad freight cars, such as well cars for transporting stacked intermodal containers, utilize articulated connectors in the form of male and female castings that mate with one another to interconnect adjacent car units. The articulated connectors are connected to the car units by being welded to center sills that in some car units are tubular stub center sills welded to the undersides of body bolsters.
Not only do the articulated connectors carry the weight of a car unit and its lading to the top of a shared wheeled truck between a pair of adjacent car units, but they also have to carry lateral forces resulting from when the car negotiates a curve in a track and the draft and buff forces between cars and car units cumulatively resulting from moving the car along with others in a train.
After lengthy use, for example 1.5 million miles, the articulated connectors of a multi-unit railroad freight car need to be replaced. In the past this has been difficult, because some of the welds attaching an articulated connector to a center sill of a car unit are located within the center sill. This was thought necessary in the past in order to have enough welded metal to transmit the draft and buff train forces resulting from operating such multi-unit cars in trains that may weigh as much as 40 million pounds. Those forces must be carried from each articulating connector into each car unit through the center sill to which the connector is attached.
Each articulated connector unit includes a respective male or female coupling portion designed to extend from a center sill toward the shared truck and the adjacent car unit. An outer portion of each articulated connector unit abuts against the extreme end of the center sill to which it is attached, and another portion of the articulated connector extends for a distance inside a box beam structure of the center sill.
While welds at the extreme end of a center sill have always been used to attach an articulated connector, it was previously also considered necessary to have additional welds. In the past, additional welding has attached the portion of the articulated connector extending inside the center sill to the interior of the center sill. This was thought necessary to ensure that the connection of the articulated connector to the center sill is capable of carrying the magnitude of forces that may be experienced when such a multi-unit freight car is operated as part of a long, fully-loaded train.
Consideration was given to the use of slot welds, but slot welds have not proven practical, and so welds inside the box structure of a center sill have been used instead.
Because of the welds located within the center sill it has been necessary to cut into the center sill to detach a worn articulated connector so that a new articulated connector can be installed. When another connector is installed similar welds have had to be used and openings made in the center sill have had to be closed. These procedures have required an undesirable amount of labor. It is therefore desired to attach an articulating connector to a stub center sill in a manner that provides sufficient strength without the requirement for internal welds within a center sill.
As embodied in the invention disclosed hereinbelow in greater detail, an articulated connector is attached to a center sill of a car unit of a multi-unit railroad freight car in such a way as to be capable safely of carrying the forces encountered in operation of such a car unit in a train without welds located inside a center sill of such a car unit.
In accordance with an embodiment of the invention a center sill in which an articulated connector is mounted has a top member with at least an end portion of substantial thickness, extending to the extreme end of the center sill and interconnected with the articulated connector through a weld joint involving the entire thickness of the top member. A portion of the articulated connector extends within the center sill, but does not need to be welded to the interior of the center sill.
In one embodiment, the attachment of an articulated connector to a center sill of a railroad freight car unit includes a weld interconnecting an outer end of a generally tubular center sill with a surface of a shoulder that extends around the articulated connector and from which a portion of the articulated connector extends within the interior of the center sill.
In one embodiment at least the top of the articulated connector is welded to the center sill in a deep groove weld interconnecting the articulated connector to a top portion of the center sill that is of greater thickness than a bottom portion or side portions of the center sill.
The foregoing and other objectives and features of the invention will be more readily understood upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings.
Referring now to the drawings that form a part of the disclosure herein, in
Both of the end car units 12 and 16 are connected with the adjacent intermediate car unit 14. As shown in
As shown in
As shown in
It will be understood that other multi-unit railroad freight cars with car units whose bodies are intended for different use than those of the multi-unit well car 10 may include full-length center sills or stub center sills of different design. So long as adjacent ends of the adjacent car units are supported by shared trucks 26, however, articulated connectors such as the articulated connector 21 may be used to support the adjacent ends of such car units on a shared truck 26. Such articulated connectors 21 are of suitably strong material such as cast or forged steel and may be attached to the center sills or stub center sills of those other multi-unit railroad freight cars in essentially the same way as described in this application for the attachment of articulated connector 21 to the stub center sills 30 and 32.
As shown in the drawings of this application, some of the usual components of car unit bodies, such as body side bearings, body side bearing arms, constant contact side bearings, and constant contact side bearing pedestals are not shown, so that they will not interfere with depiction of the articulated connectors 21 and their attachment to the car units 12, 14, and 16.
Each of the stub center sills 30 and 32 may be of welded plate construction and may include an elongate top member 36 that extends horizontally and may take the place of a central part of a bottom plate of the respective body bolster 28. The top member 36 is aligned with the length of the car unit 12 or 14 of which the body bolster 28 is a part.
The top member 36 may be of plate with a thickness 37 of 11/16 inch, as seen in
Each of the stub center sills 30 and 32 has a respective outer end portion 48, and the respective ones of the pair of mated articulated connector portions 22 and 24 are attached to the outer end portions 48 of the stub center sills 30 and 32. A female connecting unit 50 is included in a main body portion 52 of the female articulated connector portion 24 attached to the stub center sill 32 of the car unit 14, and a male connecting unit 54 is included in a main body portion 56 of the male articulated connector portion 22 attached to the stub center sill 30 of the car unit 12. The female connecting unit 50 includes a circular base plate 58 intended to fit within and be supported by a corresponding bowl 60 provided atop the center of the shared wheeled truck 26. This relationship thus provides stability of the intermediate car unit 14 about a roll axis, while supporting the weight of the adjacent end 20 of the intermediate car unit 14 and allowing the truck 26 to follow the curves in a track. It is important for each intermediate unit of such a multi-unit railcar to include at least one articulated connector having such a female connecting unit 50 to provide roll axis stability. Apart from the female and male connecting unit portions 50 and 54 the main body portions 52 and 56 of the mated articulated connector portions 22 and 24 may be similar to each other. The female and male connecting units 50 and 54 as shown herein are of one available design, and other suitable designs are also known.
The male connecting unit 54 included in the main body portion 56 of the male articulated connector portion 22 is mated with and supported by the female connecting unit 50 of the female articulated connector portion 24, with an amount of freedom of rotation about all three axes with respect to the female connecting unit 50. The female connecting unit 50 of the articulated connector 24 thus carries the weight of the adjacent end 18 of the car unit 12 and its lading to the shared truck 26, Additionally, the mated articulated connector portions 22 and 24 carry the draft and buff forces developed by a locomotive and by the brakes of a train including the multi-unit car 10 as the train moves along a track. The respective articulated connector positions 22 and 24 must be connected with each car unit 12, 14, and 16, etc., through the center sills 30, 32, etc., of the car units of a multi-unit railcar 10 in such a way as to be reliably capable of carrying such draft and buff forces, as well as being capable of carrying the weight of each car unit and its lading, and other forces such as those resulting from negotiating curves and incidental irregularities in the track on which the multi-unit car 10 is operated.
As may be seen in
Each of the articulated connector mated portions 22 and 24 may be attached in the same manner to the respective stub center sill 30 or 32 with which it is associated. The attachment of the articulated connector male mated portion 22 to the stub center sill 30 will be described now in detail, and it will be understood that the attachment of the female articulated connector mated portion 24 to the stub center sill 32 is essentially similar.
The top member 36, side members 38 and 30 and 40, and bottom member 42 of the stub center sill 30 are all typically, but not necessarily, terminated in alignment with each other, and thus may define an outer end plane 70 of the outer end portion 48. All of the center sill bottom and side members 38, 40, and 42 may be constructed of steel plate members of equal thickness, but at least an outer end portion 72 of the top member 36, extending to the outer end plane 70 over a distance 73 of, for example, at least 10 inches, and preferably 15 inches or more, may have a top member thickness 74 of at least 1⅛ inch, when of commonly used steel. The greater thickness 74 of the outer end portion 72 of the top member 36 may be established as shown in
The main body portion 56 or 52 of each of the articulated connector portions 22 and 24 ends at a shoulder 78 located adjacent to and facing toward the outer end plane 70 of the respective stub center sill 30 or 32 to which it is attached. Referring now specifically to the attachment of the articulated connector 22 to the stub center sill 30, as best shown in
As shown in
As seen in
As a result of the top member thickness 74 of the outer end part 72 of the top member 36 of the stub center sill 30 at the outer end plane 70, the portion of the groove weld 81 connecting the outer end portion 72 of the top member 36 of the center sill 30 with the main body portion 56 of the articulated connector portion 22 includes a substantial volume and mass of welded metal. With portions of the groove weld 81 also connecting the shoulder 78 of the male articulated connector portion 22 to the side members 38 and 40 and the bottom member 42 of the outer end portion 48 of the stub center sill 30, the male articulated connector portion 22 is attached to the stub center sill 30 with ample strength to sustain the loads the articulated connector 22 can reasonably be expected to incur.
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.
Number | Name | Date | Kind |
---|---|---|---|
2073013 | Jabelman | Mar 1937 | A |
3399631 | Weber | Sep 1968 | A |
4315465 | Cordani et al. | Feb 1982 | A |
4751882 | Wheatley et al. | Jun 1988 | A |
5207161 | Pileggi et al. | May 1993 | A |
6167813 | Kaufhold | Jan 2001 | B1 |
6510800 | Zaerr et al. | Jan 2003 | B1 |
6546878 | Smith et al. | Apr 2003 | B1 |
Number | Date | Country | |
---|---|---|---|
20190054934 A1 | Feb 2019 | US |