Patent Application
20080302266
The present invention relates generally to railcars and, more particularly, to a temperature controlled railway car support post.
Over the years, general purpose railway boxcars have progressed from relatively simple wooden structures mounted on flat cars to more elaborate arrangements including insulated walls and refrigeration equipment. Various types of insulated boxcars are presently manufactured and used. A typical insulated boxcar includes an enclosed structure mounted on a railway car underframe. The enclosed structure generally includes a floor assembly, a pair of side walls, a pair of end walls, a roof and various support posts. The side walls, end walls and roof often have an outer shell, one or more layers of insulation and interior paneling.
The American Association of Railroads (AAR) sets various design requirements for insulated and refrigerated railcars. One such requirements relates to a heat transmission value, ua. The lower the ua value, then the less refrigeration needed for a refrigerated car. Thus, it is desirable to have a low a ua as possible for an insulated or refrigerated railcar. Much of the heat loss for such a railcar is through the side posts which are typically made of steel. The steel of the side posts is a much better conductor of heat than foam insulation used in the cars, so the heat transfer through these posts is large despite their smaller cross-sectional area. Fiber reinforced plastic (FRP) is typically used in the manufacture of many insulated and refrigerated railcars, such as for interior paneling.
The present invention provides a railcar system and a method of manufacturing a railcar system that substantially eliminates or reduces at least some of the disadvantages and problems associated with previous railcar systems and methods.
In accordance with a particular embodiment, a railcar system includes a plurality of railcar walls and a plurality of railcar support posts each coupled to at least one of the plurality of walls. Each of the plurality of support posts comprises a web portion comprising a non-metallic material and a plurality of flange portions coupled to the web portion, the flange portions comprising a metallic material.
The non-metallic material may comprise fiber reinforced plastic or wood. The plurality of flange portions may each comprise a metal component forming an approximately ninety degree angle. The plurality of railcar support posts may each be welded to at least one of the plurality of walls. The plurality of flange portions may each be bonded to the web portion using glue or rivets. The plurality of flange portions may be configured to withstand bending forces imposed upon the support posts. A cross-section of each of the support posts may comprise a generally I-configuration.
In accordance with another embodiment, a method of manufacturing a railcar system includes coupling a plurality of flange portions to a plurality of web portions to form a plurality of railcar support posts. Each web portion comprises a non-metallic material, and each flange portion comprising a metallic material. The method includes coupling each of the plurality of railcar support posts to at least one of a plurality of railcar walls.
Technical advantages of particular embodiments of the present invention include a temperature controlled railcar support post with a web portion that comprises a non-metallic material. Thus, the web portion conducts less heat than the metal web portions of conventional support posts. Accordingly, an insulated or refrigerated railcar comprising the support post will lose less heat than conventional insulated or refrigerated railcars.
Other technical advantages will be readily apparent to one skilled in the art from the following figures, descriptions and claims. Moreover, while specific advantages have been enumerated above, various embodiments may include all, some or none of the enumerated advantages.
For a more complete understanding of particular embodiments of the invention and their advantages, reference is now made to the following descriptions, taken in conjunction with the accompanying drawings, in which:
In some embodiments, support posts 20 may be utilized in an insulated railcar, such as one that may be refrigerated. Typical such support posts comprise steel in order to withstand forces applied during railcar operation. Particular embodiments provide a low heat-transfer (LHT) support post that can replace conventional steel posts without severely impacting the manufacturing process. In particular embodiments, support posts 20 may include non-steel portions, such as non-steel web portions, in order to reduce heat transfer in the post and therefore provide greater insulation for the railcar. In some cases, such non-steel portions may comprise fiber reinforced plastic (FRP). A support post made completely of FRP may not be practical because it may not match the stiffness of a conventional steel post and may allow excessive distortion of the side. In addition, it may have to be bonded to a railcar side sheet, and this would require a complete re-design of the railcar manufacturing process.
Web portion 110 comprises FRP. Thus, web portion 110 conducts less heat than the metal web portions of conventional support posts. An insulated or refrigerated railcar comprising support post 100 with web portion 110 will therefore lose less heat than conventional insulated or refrigerated railcars with support posts having metal web portions. The railcar having one or more of support posts 100 will therefore also have a lower ua heat transfer value. While web portion 110 comprises FRP, web portions of railcars in other embodiments may include, in addition to FRP or in alternative to FRP, other non-metallic materials, such as other types of plastic or wood.
In the illustrated embodiment, web portion 110 is coupled to metal angles 120 through a bonding process. This bonding process may utilize an adhesive such as glue to couple web portion 110 to metal angles 120. Rivets 130 may be used to hold the web portion in place during the bonding process, for example, until the bonding glue sets. In some embodiments, the rivets may be removed after the bonding process is complete. Other embodiments may utilize other methods of coupling a web portion to a flange portion for a railcar, such as a bonding process using an adhesive such as glue.
An additional advantage to support posts described herein is that the bonding portion (e.g., portion 125 of
As discussed above, while particular embodiments are illustrated using support posts with I-beam configurations, support posts having other shapes and configurations and with non-metal web portions may be used.
Support posts in particular embodiments may have the same flexural stiffness as conventional posts and may thus replace conventional posts with minimal impact. In some cases, the ua value for an entire railcar with support posts described herein may improve 22 points or more.
Although the present invention has been described in detail with reference to particular embodiments, it should be understood that various other changes, substitutions, and alterations may be made hereto without departing from the spirit and scope of the present invention.
Numerous other changes, substitutions, variations, alterations and modifications may be ascertained by those skilled in the art and it is intended that the present invention encompass all such changes, substitutions, variations, alterations and modifications as falling within the spirit and scope of the appended claims.
