Welding method for pneumatic outlet bottom cover assembly

#This invention relates to railroad car manufacture and, more particularly, to a welding method for manufacturing a bottom cover assembly to the pneumatic outlet of a railroad car.

#In the manufacture of pneumatic outlet assemblies for a railway hopper car, one problem encountered is in the fabrication of a bottom valve cover assembly for the outlet. Assembly of the cover requires that two or more longitudinal sections be joined together. Typically this is done by welding adjacent sections together, this welding operation including both an internal and an external weld. The sections comprising the bottom valve cover are generally tubular in shape. Consequently, forming the cover may be thought of as joining together sections of pipe. As is well known in the art, it is sometimes necessary during a welding operation to use inserts in the form of gaskets, for example. The inserts, in turn, may be either wholly or partially consumable.

#Most consumable, or partially consumable, inserts are used in joining pipe where welding access to the inside of the pipe is extremely difficult. Examples of welding inserts are shown, for example, in U.S. Pat. Nos. 4,611,830, and 4,652,019. Inserts like those shown in these patents are used to minimize obstructions on the inside surface of a pipe. Here, obstructions are harmful in two ways. First, obstructions inhibit the efficient discharge of lading from a hopper car. Second, obstructions can cause some lading to be retained within the outlet. This lading can then contaminate subsequent ladings shipped in the same car. For certain ladings, any contamination essentially ruins the value of the lading. Hence, there may be a significant economic impact to the owner or lessor of the car resulting from the construction of the cover assembly.

#FIG. 1 is an elevational view of a portion of a pneumatic outlet for a railway hopper car;

#FIG. 2 is a sectional view of the outlet taken along line 2--2 in FIG. 1;

#FIG. 3 is a plan view of a section of a bottom cover assembly for the outlet;

#Referring to the drawings, Figs. 1 and 2 illustrate a pneumatic outlet A for a railway hopper car (not shown). The construction and operation of pneumatic outlets are well known in the art and will not be described in detail. In general, the outlet, which mounts beneath a hopper of the railway car, comprises a flow tube B having a cap C at each end closing off the tube. When the caps are removed, and appropriate attachments are made, a flow of air is directed through the outlet. Particulate lading carried in the hopper is entrained in this air flow and the railcar is unloaded. The flow tube is comprised of two or more tubular metal members (B1 and B2 in FIG. 5), which have generally coincidentally configured metal edges or ends E1 and E2 respectively. These edges may be straight, but are preferably rounded. Also preferably, the tubes are formed of aluminum. To form tube B, the abutting ends of the respective members are welded together according to the method to be described hereinafter. The upper ends U1 and U2 of tube B attach to the respective lower ends L1 and L2 of sloping sheets S1 and S2 of the outlet assembly. The upper end of tube B is open as indicated at 0. A valve member M is adjacent this opening and is pivotally mounted at P to move between respective closed and open positions in order to close and open the tube to flow of lading from a hopper H.

#Referring to FIGS. 3-6, FIG. 4 provides a profile of one of the tube sections (section B1) at one of its ends. In order to form tube B, abutting ends E1 and E2 of the adjoining tube sections are welded both interiorly and exteriorly as indicated at WI and WE in FIG. 4. The method of the present invention is for creating these weld joints between the two metal members B1 and B2. In addition to their generally coincidentally configured abutting edges, the tubes also have generally coincidental first surfaces 1A and 1B adjacent to and on one side of the edges, and generally coincidental second surfaces 2A and 2B adjacent to and on the other side of the edges.

#The first step in practicing the method of the present invention is to chamfer the corners of the respective edges and first surfaces as indicated at 3A and 3B in FIGS. 5 and 6. As shown, the result of this chamfering step is to create a generally V-shaped groove 4 between the respective first surfaces 1A and 1B. The chamfer at each of the edges is formed so as to create the depth of groove 4, this depth being approximately 75% the thickness of tubes B1 and B2. Additionally, the depth of groove 4 is approximately equal to one-half the width thereof, prior to a gasket 5 being placed between the abutting edges of the tubes. The abutting edges E1 and E2 respectively form 90.degree. angles with the second surfaces 2A and 2B; and, the chamfering at the respective corners between the edges and surfaces 1A and 1B form 45.degree. angles with respect to the second surfaces.