Fixture for use in semi-automatic reconditioning process of a railcar articulated connector

A machining fixture for semi-automatically reconditioning an articulated connector is provided. The fixture comprises a housing having at least two side walls, a top plate having a first opening connecting the side walls, and a bottom plate connecting the side walls, the side walls, top plate, and bottom plate defining an interior space. The fixture also includes a clamping mechanism attached to at least one of the side walls, the clamping mechanism comprising a curved hook portion, the curved hook portion being laterally adjustable.

BACKGROUND

Multi-unit railroad cars are typically interconnected using couplings, such as articulated connectors, to link one unit to the next. Most often, the connectors include a male casting portion mounted to the end structure of one of the rail car units which is joined to a female casting portion located on the end structure of the adjacent rail car unit. Joining of the male and female portions results in an articulated connection between the rail car units. American Steel Foundries, Inc. (ASF) of Granite City, Ill. and Meridian Rail, Inc. (formerly and hereinafter National Castings) of Lombard, Ill. manufacture the most frequently used connectors of this type in the U.S. industry.

The cargo portion of a railroad train comprises a plurality of multi-unit rail cars linked in this fashion. As such, the driving locomotive is only acting directly on the car adjacent to it, which is then joined to the next unit, etc. The pulling, or pushing, of the rail car units by the locomotive creates a significant level of stress on each connector as each bears the entire force of the rest of the rail cars. Any contact between the male and female casting portions and their associated components results in wear on those contact areas of the connectors.

The stress placed on the connectors results in wearing of the metal at several points of contact between the male and female portions of the connectors, or their respective components, due to impact and frictional contact. Particular points of wear include the bottom ring surface and anterior surfaces of the bores of the female portion of the connector, and the bottom bearing surface, the spherical anterior surface of the opening32(as shown inFIG. 1) and the front spherical surface of the male portion of the connector. Commonly owned U.S. Pat. Nos. 7,490,393 and 6,944,925 describe processes for reconditioning the front surface30of the male portion of the connector and the front surfaces of the bores of the female portion of the connector as well as the anterior surfaces of the bores of the female portion of the connector.

As articulated connector castings are an integral part of the car structure and are difficult and expensive components to replace, it is favorable to repair or recondition the connectors as opposed to replacing them or the entire rail car. Connector castings can commonly travel 1,200,000 miles or more without the need for significant maintenance. In the past, reconditioning of most rail car components has involved removing various parts from the rail car and reapplying them back into place after such reconditioning. Some couplers have been reconditioned in this way, especially those removable by design. Articulated connectors, however, are not suited for such removal and repair since they are integral to the car and such repair would be inefficient, time consuming, and expensive.

It is therefore an object of the present invention to provide a method of reconditioning rail car connectors such that the reconditioning occurs while the castings are still attached to the rail cars. It is a further object of this invention to simplify the measurement of portions of the connectors ensuring that the connectors are reconditioned to the appropriate dimensions, including the use of appropriate gauges. It is yet a further object of this invention to provide a method of reconditioning rail car connectors utilizing gauges to take measurements of the connectors while still attached to the rail car. It is still another object of this invention to provide a method for reconditioning rail car connectors using less labor-intensive processes by eliminating the need to invert a rail car in order to perform reconditioning of the connectors, although the process can be used on inverted rail cars as well.

BRIEF SUMMARY

In a first embodiment, a machining fixture for semi-automatically reconditioning an articulated connector is provided. The fixture comprises a housing having at least two side walls, a top plate having a first opening connecting the side walls, and a bottom plate connecting the side walls, the side walls, top plate, and bottom plate defining an interior space. The fixture also includes a clamping mechanism attached to at least one of the side walls, the clamping mechanism comprising a curved hook portion, the curved hook portion being laterally adjustable.

In a second embodiment, an assembly for semi-automatically reconditioning an articulated connector is provided. The assembly comprises a welding fixture including a fixture shaft extending upwardly from the welding fixture and a plurality of clamps for securing the welding fixture to a male casting, a welding device including a torch nozzle assembly for applying weld material a control unit to provide for the flow of weld material to the torch nozzle, an opening for attachment to the fixture shaft, and a weld cam having a least one detent, wherein an interrupted weld pattern is formed on the bottom bearing surface of the male casting when the weld cam engages with the control unit.

In a third embodiment, an assembly for semi-automatically reconditioning an articulated connector is provided. The assembly comprises a welding fixture including a fixture shaft extending upwardly from the welding fixture and a plurality of clamps for securing the welding fixture to a male casting, a welding device including a torch nozzle assembly for applying weld material, a control unit to provide for the flow of weld material to the torch nozzle, an opening for attachment to the fixture shaft, and a weld cam, wherein an uninterrupted weld pattern is formed on the bottom bearing surface of the male casting when the weld cam engages with the control unit.

Referring toFIGS. 1-2generally, the articulated connector castings being reconditioned are attached to the rail car end structure (not shown) and usually include a male casting10located on one rail car unit and a female casting12located on the adjacent rail car unit such that the male and female castings can interlock, joining the rail car units to form a multi-unit rail car. When the female and male castings are brought together, bores24,26of the female casting are aligned with the male casting opening32such that a pin16can be inserted, securing the male and female castings and their internal components together to complete the connector. The connectors are articulated such that they can rotate about the pin and have vertical angularity, allowing the rail car units to pivot relative to each other during movement around curved tracks and over undulating terrain.

As noted above, there are two dominant articulated connector types used in joining rail car units, namely ASF connectors and National Castings connectors, although other connector types exist which can be similarly accommodated by this invention. The following description refers to the ASF connectors. However, this description is exemplary of rail car connectors generally. As such, the following description of the invention is tailored to industry standards, but the invention could be modified to accommodate specific connectors used, including but not limited to National Castings connectors.

The exemplary ASF connector, as shown inFIGS. 1 and 2, comprises a male casting10and a female casting12. The female casting12is generally U-shaped in cross section to receive the male casting10. The female casting12includes a top portion18and a bottom portion20, which are generally planar and are joined by sidewalls22and a generally concave back wall23. The sidewalls22, back wall23, top portion18and bottom portion20define the generally U-shaped receiving cavity34of the female casting. Both the top portion18and the bottom portion20of the female casting include a cylindrical bore24and26, respectively, which are aligned with one another. Moreover, the bottom portion20includes a spherical ring surface25.

The female casting additionally includes a wedge system located along the concave back wall23. The wedge system includes a wedge36and a follower block38. The follower block38is designed to conform to the spherical contour of the portion of the male casting with which it contacts. The wedge is then placed between the back wall23and the follower block38, holding the follower block38in place and providing pressure. The wedge is held in place by gravity and drops as wear occurs within the system to maintain a low longitudinal slack condition, thereby keeping the follower block38in constant contact and compression with the male casting10.

The male casting10includes a forward end28, which is a generally U-shaped projection of generally constant thickness. The male casting10has an opening32with generally square features at the side nearest the attaching car unit, or posterior surface70of the opening32, and with a U-shaped concave surface nearest the opposite, anterior surface54of the opening. The male opening32is different in shape than the female bores24and26as the anterior surface54of the male opening32is concave and generally spherical in shape and the opening32has an overall greater volume than that required for insertion of the pin. As such, a pin bearing block31is inserted into the opening32and mates with the anterior surface54of the opening, as shown inFIG. 2. The shape of the pin bearing block31is generally spherical along the end contacting the anterior surface54of the opening32, to compliment the opening, and has a generally vertical concave cylindrical shape along the opposite side to receive the pin16. When the pin bearing block31is placed in the opening32, the concave cylindrical side of the pin bearing block31and the posterior end70of the opening32define the area to receive the pin as described below.

The forward end28of the male casting is generally U-shaped to compliment the interior of the female casting in shape. The forward end28includes a front surface30at the far end of the male casting which includes the generally U-shaped area. The front surface30is the portion of the male casting in contact with the follower block38when the male casting10is inserted into the female casting12. The forward end28of the male casting also includes a bottom bearing surface33. The bottom bearing surface33comes into contact with the spherical ring surface25when the male casting10is inserted into the female casting12.

Upon assembly, as shown in cross-section inFIG. 2, the male casting10, specifically the forward end28is inserted into the cavity34of the female casting12. The bottom bearing surface33of the male casting is positioned above the spherical ring surface25such that the opening32in the male casting is aligned with the bores24and26of the female casting. When the two bores24,26are aligned with the opening32, a cylindrical pin16can be inserted through them. The pin16is inserted into the bore24in the top portion18of the female casting and then passes through the opening32in the male casting10, which includes the pin bearing block31, and then passes further to engage the bore26in the bottom portion20of the female casting12. The top of the pin is preferably secured to the top of the female casting.

The wedge system works to eliminate slack from the connector system by applying pressure on the male casting and hence on the pin bearing block cylindrical surface bores and pin. Due to the wedge system and the general construction of the castings, significant wear occurs in selective areas. On the female casting, wear may occur on the spherical ring surface25and the anterior surfaces103of the female bores24and26as the compressive forces from pulling cars pushes the pin16against those surfaces. Conversely, the posterior surfaces102of the female bores receive negligible wear, as a result of the wedge system not allowing pin stress on this surface. On the male casting, wear occurs along the bottom bearing surface33and the spherical anterior surface54of the opening32as the pin bearing block31rides against it. Conversely, the posterior surface70of the male opening32receives no wear under normal operating conditions. The male casting also experiences significant wear on the front spherical surface30as a result of contact with the follower block38and compressive forces from other rail car units.

During use of connected rail car units, wear can occur in at least these areas as specified above due to friction caused by the pivoting and movement of the rail car units relative to one another. The following are methods for reconditioning and repairing rail cars at these common sites of wear either while the connectors are still attached to the rail car or when the connectors have been detached. The reconditioning returns the worn parts of the connectors back to their proper dimensions to ensure peak performance upon re-connection of the rail car units.

Manual Reconditioning of the Articulated Connector

Several methods are described herein to recondition articulated connectors. While ASF male castings are referenced below, as known to those of ordinary skill in the art, the methods and equipment described below may readily be adapted to be applied to other types of male castings, such as, for example, from National Castings, as well as to female castings. For example, the process described below could be applied to the bottom surface3000of the female casting12show inFIGS. 1 and 2.

The male castings should be prepared so that an accurate measurement can be taken to determine if reconditioning is required, particularly with respect to the areas described above. Such preparation includes cleaning the surfaces of rust, dirt, grit, grease, lubrication residue, or the like. Substances such as grease, grime and lubricants can be scraped from the surfaces. Remaining contaminants can be burned off with a torch or ground away. Metal upsets on the surfaces in need of reconditioning should be carefully machined smooth to prevent cold laps during later welding. The male castings are then measured to determine if reconditioning is required. Any portion of the casting that exists before the weld is applied can be referred to as being “parent casting material.”

As noted above, the bottom bearing surface33and front surface30of the male opening32of the male casting are prone to wear as they are in frictional contact with the spherical ring surface25and follower block38respectively. The reconditioning of the bottom bearing surface is discussed below. As to the front surface30, an example of reconditioning techniques may be found in U.S. Pat. No. 7,059,062, assigned to TTX Company, which is herein incorporated by reference in its entirety.

FIG. 3generally shows the steps of the applicable reconditioning process. Once the area to be measured has been prepared and cleaned300, the bottom bearing surface33of the male casting10is measured302,304to determine if the bottom bearing surface33has worn such that it needs reconditioning. Any suitable gauge may be used so long as it may be swept along the bottom bearing surface to determine if reconditioning should be performed.

An exemplary gauge based on the gauge disclosed in U.S. Pat. No. 6,944,925 is shown inFIGS. 24, 24aand24b. The preferred gauge2401, as shown inFIGS. 24, 24a,24band24c, for use in measuring the ASF male connector is a pivot gauge, which preferably includes two members: a base42and a swing arm assembly44. The base42is generally a block-shaped member having a plurality of sides as shown. The top of the base42includes an opening78to receive a portion of the swing arm assembly44. The front side of the base42has a relatively spherical surface52to engage the anterior surface54of the bore32in the male casting10, which has a complimentary shape. The complimentary shapes allow the proper vertical relationship of the gauge to the male casting to ensure accurate measurement of the worn portion. The rear side56of the base preferably includes an opening58to receive a screw jack assembly60. The screw jack assembly60includes a threaded rod62having a brace end64and a nut66, forming an expanding clamp brace. The brace end64is configured to brace or secure the base42against the interior of the male bore32. Preferably, the brace end64has three legs68contacting the posterior surface70of the male bore32. The nut66, when turned, extends or retracts the brace end64from the base42. As a result, the turning of the nut66can extend the brace until it is flush with the posterior surface70of the male bore32securing the base42of the pivot gauge in the male bore32. The anterior surface54and posterior surface70are typically unworn or minimally worn portions of the bore32that are sufficient for reference measurement for refinishing.

The swing arm assembly44comprises a swing arm44a, a cylindrical holder44b, and a plate44c. The swing arm44ais generally L-shaped, and includes an extension arm portion74and a measurement arm portion76. The length of the extension arm74is determined by the dimensions of the male casting generally, including the contact surface30and the male bore32.

The swing arm assembly44is pivotally connected to the base. Plate44cis secured to the base42by a countersink bolt48located on the plate44c. The countersink bolt48is received in opening78in the base42. The cylindrical holder44b, which preferably has a top portion43and a bottom portion45, is then pivotally attached to the plate44c. The bottom portion45of the cylindrical holder41is preferably inserted into a hole (not shown) in plate44cand is secured to the plate, preferably with a c-shaped clip (not shown) inserted into and around a smaller diameter of a groove in the bottom portion43of the cylindrical holder41.

The top portion43of the cylindrical holder41includes a notch47to receive the extension arm74of the swing arm44a. Additionally, an inline hole49extends horizontally through the cylindrical holder41which aligns with a similar hole (not shown) in the extension arm. A pin can then be inserted through the hole49and the hole in the extension arm74, securing the extension arm74to the cylindrical holder41.

The swing arm assembly results in the plate44cbeing secured to the base42via countersink bolt48, the cylindrical holder44bbeing removably and pivotally secured to the plate44c, and the swing arm44abeing removably and pivotally secured to the cylindrical holder44b. The swing arm44ais thus capable of pivoting generally vertically up from the base around the inline hole49and pin. This allows the swing arm44ato be pivoted up and away from the male casting10, when desired. The cylindrical holder44band hence the swing arm44aare additionally able to pivot horizontally around the axis of the cylindrical holder44b, allowing the swing arm44aand its contour edge84to sweep along a desired range of the male casting contact surface30.

The swing arm44aadditionally includes a flat portion46, which is part of the extension arm74that contacts the plate44cand ensures the proper relationship between the contour edge84and the spherical surface52of the base42. The measurement arm76then extends downwardly from the extension arm74. The measurement arm76includes a front edge82and a contoured edge84. The curve of the contour edge84is designed to conform in shape with the contact surface30of the male casting10of the connector. The contoured edge84can swing the entire range of the contact surface30of the male casting10. The length of the extension arm74is such that the contour edge84of the swing arm44ais less than approximately ⅛″ from the contact surface30of a male casting10having no wear.

The preferred gauge2401of the present invention also includes a rotating component2400attached to a mounting piece2402that includes a bolt2404, a bushing2403and a spacer2405. The gauge2401is shown in position inFIG. 24c. Once the gauge2401is locked in place as described above, the rotating component2400is rotated around to measure the amount of weld that needs to be built up, or, if the rotating component is removed and flipped over, is used to measure whether the surface33needs further grinding to get back to the proper dimension.

Once it is determined that the male casting10of the connector requires reconditioning (i.e.,FIG. 3, 302, 304), the bottom bearing surface33is divided into octants (step305) and marked using a soap stone as shown inFIG. 25. Next, the bottom bearing surface33and the surrounding areas are preheated307to between 300-500° F. and maintained at this temperature range during the welding process, for example by use of a torch with a heating tip. It is preferable to use a non-contact thermometer to identify that the preheat temperature is within the desired range. Alternatively, the male casting10may be heated using an induction heating cable to automatically preheat the casting and maintain the casting at the desired temperature during welding. Induction heating may also be used to control slow cooling during the process. Referring toFIGS. 26 and 27, an exemplary embodiment of an induction heating cable2600and its application to a male casting10is shown. The induction heating cable2600is typically controlled by a commercially available induction heating system, such as a MILLER PROHEAT 35 Induction Heating System, although other induction heating systems may be used. In operation, the induction heating cable2600is wound into circular, oval shapes2602having a minimum of two full windings as shown inFIG. 26. The cable2600windings may consist of a single layer or multiple layers, as required to produce the required casting temperature during the reconditioning process.

In the male casting10reconditioning process, there are preferably at least two of these oval shaped cable windings2602, which are symmetrically spaced from the approximate midpoint of the induction heating cable. These oval shaped windings2602are applied symmetrically to each side of the male casting10as shown inFIG. 27. The windings2602are shown in insulating saddle bags2604in the illustrations, but any insulating material may be used between the cable windings2602and the male casting10surface to separate the windings2602from direct contact with the male casting10in order to prevent heat damage to the induction heating cable2600.

The affected area is then built up with weld306one octant at a time, preferably using a specially modified STOODY hard facing welding wire (0.045″ diameter for example, although other diameters may be used) to allow overhead welding and use of CO.sub.2 gas. An equivalent wire having similar chemistry and welding characteristics may also be used. The chart below provides exemplary wire compositions and machine settings, but other compositions will be evident to those skilled in the art:

As shown inFIG. 25, a weld bead2500is preferably applied along each soap stone marking making up the octants from the center hole32to the outside edge2502of the casting. Then, beginning at the outside edge2502, weld2500is applied radially moving inward until the entire octant2504is welded. The weld may also begin on the inside edge of the casting and be applied moving radially outward until the entire octant2504is welded. Weld is applied to the octants2504in the order shown by numbers 1-6 inFIG. 25, leaving two diagonally opposite octants2505,2506unwelded. After the first six octants2504are welded the rotating component2400is removed and the remaining two may be welded.

Optionally, and as a precaution, the surfaces of the gauge2401shown inFIGS. 24a, 24band 24csubject to weld spatter should be lightly coated with a spatter resistant product prior to welding. Preferably, the application of weld to the worn surfaces should be performed in a relatively still air environment to prevent loss of shielding gas and fast cooling. The surface temperature of the casting should not be allowed to drop below 300° F. at any time during the build-up process. It may therefore, be necessary for the casting to be reheated during the process. If the welding process is interrupted for any significant length of time, the welded area must be thoroughly covered with an insulating blanket to prevent fast cooling and potential cracking of the weld.

Welding practices known in the art regarding the removal of all slag, oxide scale and spatter between passes should be followed. Weld should be finished so as to not produce a notch effect at the junction of the weld with the parent metal and every precaution should be taken to avoid abrupt changes in section thickness at the line of fusion. Following the welding process, the casting is slow cooled to ambient temperature using insulating blankets or an equivalent means such as an insulating box as shown inFIG. 20. Cracks, incomplete fusion, overlaps, undercut, unfilled craters, voids, and other defects can be highly problematic and should be avoided. The preheating and slow cooling steps during the process help reduce the potential for cracking. For porosity, no rounded indications greater than 3/16 inches long, and no 6 inch square regions containing ten or more rounded indications are preferred.

Following the slow cool, the insulating blankets are removed. The rotating component2400is then reapplied in an inverted position. The restored bottom bearing surface33then is manually ground308to within a desired tolerance of the rotating component2400blade surface. The desired standards will depend on machining and/or industry requirements, but in one preferred embodiment it is within 1/16 inch of nominal new dimension. Grinding generally involves the removal of excess weld, metal, or other material. The weld additionally is blended into existing adjacent surfaces.

Once welding306and grinding308are accomplished, the bottom bearing surface33is measured, such as by passing a gauge over the surface33, to re-qualify the part310and ensure proper repair has occurred such that no wear or over buildup remains and that the dimensions are correct. If desired tolerances are not met, the bottom bearing surface should again be reconditioned as described above. Whether welding306and grinding308are both required will depend on the quality and remaining thickness of the weld. After cooling, the restored area is tested, such as through the use of dye penetrant or magnetic particle inspection, to determine that the quality of the restored surface is free of defects.

Advantageously, the above reconditioning method overcomes problems in the prior art. Notably, when male castings wear, they usually are removed and replaced. This is expensive and wastes materials. The above method avoids this drawback. Furthermore, the octant method as described reduces surface cracks such as radial cracks in the weld material.

With respect to the application of this process to a female bottom surface3000, the general principle of building the surface up with a weld material and then grinding (or machining the surface in a semi-automatic process as described below) also applies.

Semi-Automatic Process for Reconditioning Connectors

A semi-automatic technique will now be described as implemented for the reconditioning of an ASF male articulated connector casting. It is contemplated that the presently preferred technique is applicable to other connector castings, such as male National Castings articulated connector castings, and the female casting counterparts thereof.

As described above and shown inFIGS. 1 and 2in the present disclosure, the ASF male casting10includes a forward end28having a bottom bearing surface33. The bottom bearing surface of the male casting is subject to wear caused by contact with the spherical ring surface25within the female casting12during use.

As noted in the description of the above method, reconditioning of the bottom bearing surface33on the male casting may be accomplished through the manual application of a grinding process once the surface has been rebuilt through welding. The grinding procedure, while more desirable over the known method of removing and replacing the entire casting, may take many hours to complete by hand due to the superior strength of the materials used in the casting and the weld. Moreover, given the length of the task, it is often advantageous to flip or invert the cars with the male casting, so that the bottom bearing surface is not being reconditioned upwardly. This may present challenges due to the large size and weight of the car and casting. Moreover, the manual reconditioning process usually requires the rail cars to be brought to a repair shop facility. It therefore may be desirable to automate the welding and metal removal process.

In accordance with the present invention, a welding fixture800is provided to assist in semi-automatic reconditioning of an ASF male casting. Turning toFIGS. 13A-13B, the welding fixture includes a support plate802and a base plate804extending substantially perpendicular from the support plate802. The base plate804includes a cutout816that, as explained below, allows a welding device to be connected with the welding fixture800. It also includes a catch plate806that extends downwardly at an angle relative to the base plate. The catch plate806engages to an inner surface of the anterior surface54of the opening of the male casting10to secure the welding fixture800to the male casting. While the catch plate806can be angled as desired in order to secure the welding fixture to the male casting, in a preferred embodiment the catch is angled downwardly at approximately 54 degrees to the base plate.

A pair of side arms808extend downwardly from the base plate804, such that a side arm808is on either side of the male casting10when the welding fixture800is attached to the casting. As explained further below, each of the support plate802and side arms808includes a knob810that, when tightened, allows a screw812associated with the knob to engage the male casting and secure the welding fixture800to the male casting10. A fixture shaft814extends upwardly from the top plate. The fixture shaft provides for the attachment of a welding assembly to semi-automatically build up the weld on the bottom bearing surface of the male casting.

A machining fixture assembly200is also provided to assist in the semi-automatic reconditioning of an ASF male casting. After the welding step as described above, the male casting10is removed from the welding fixture800and placed and aligned in the machining fixture200. Preferably, the fixture includes an adjustable, rigid frame apparatus as shown inFIGS. 4A-4H. Turning first toFIGS. 4A-4B, the fixture200includes a horizontally positioned top plate202and a corresponding horizontal bottom plate204. The top plate202includes a first opening206and a pair of handles208. The bottom plate204includes a second opening210, which is substantially aligned with the first opening in the top plate202. Preferably, and as shown inFIG. 4I, the first and second openings206,210are aligned such that the measurements L1and L2are within approximately 1/32 inches of each other and where the measurements D1and D2are within approximately 1/16 inches of each other. However, in other embodiments other tolerances may be used.

The top and bottom plates202,204are connected via a pair of spaced, vertical sideplates212rigidly attached to and extending between the top plate202and the bottom plate204. Gussets214are mounted in various corners of the frame of the fixture200to reinforce the rigidity of the structure. In the rigid frame of the fixture200, the horizontal plate202and204and the vertical sideplates212define an interior space216. The fixture200also includes a centering portion2000with a tongue4000which acts as a guide to help center the fixture200laterally on the connector10.

The fixture200incorporates a clamp assembly218to allow attachment of the fixture200to a male ASF casting. Preferably, the clamp assembly218includes a hook220and a threaded rod219that, as explained further below, allows the hook220to be moved in the direction of the arrows222inFIG. 4D. The clamp assembly218further includes an alignment plate224and at least one spacer226attached to the alignment plate224, such that they are “stacked” in a horizontal direction (i.e., arrows222). A pair of gauge support bars228are attached to the inner surfaces of the sideplates212and, as shown inFIG. 4B, they extend outwardly from the sideplates212. As shown inFIG. 4J, the fixture200also includes a pair of holders230on one of the sideplates212to hold a gauge232. As explained below, the gauge232is used in conjunction with the support bars228to check the bottom bearing surface33of the male casting. Referring toFIG. 4H, in a preferred embodiment it is desirable to have an upper surface234of the support bars228be approximately perpendicular to a surface236of the outermost spacer226to within 0.1 degrees, and to have the upper surfaces234of the support bars228be approximately parallel to each other to within 0.1 degrees.

First and second bearings238,240are included and are centered within the first and second openings206,210. The first bearing238is disposed on a top side242of the top plate202and the second bearing240is disposed on a top side244of the bottom plate204. The first and second bearings238,240should be substantially aligned. One way of aligning the bearings is through the use of an alignment tube246(FIGS. 4F-4G). In one desired embodiment, the bearings may be aligned such that the vertical axis defined by Y1is parallel to axis defined by Y2to within 0.1 degrees and the vertical axis defined by Y3is perpendicular to horizontal axis defined by X1within 0.1 degrees.

FIGS. 4A-4Eshow an ASF male casting10attached to the fixture. In particular,FIG. 4Cshows that the threaded rod219is loosened so that the hook220draws nearer to the alignment plate224. This allows the clamp assembly218to be lowered into the opening32of the male casting10. The threaded rod219is then tightened. Specifically, and as shown inFIGS. 4D-4E, the threaded rod219should be tightened so that the hook220and anterior opening surface54are in contact with each other and so that the outermost spacer226and posterior bore surface70are in contact with each other.

An exemplary embodiment of the semi-automatic reconditioning technique for the ASF male articulated connector casting will now be described.FIG. 5illustrates a flow diagram of one embodiment of the preferred method. As shown at552, the male casting of the ASF articulated connector10is prepared for reconditioning. This preparation is similar to that of the previously described embodiments above. In general, however, dirt, grease, lubrication residue, and other contamination must be removed from the bottom of the male bearing surface of the casting prior to the restoration procedure. Preferably, this is performed through burn off and/or machining (i.e. grinding). Burrs are then removed from the inner and outer diameters of the bottom bearing surface. The fixture800is mounted553to the casting10and the casting10is preheated555to between 300°-500° F.

The welding operation may then proceed as at554in order to add weld metal to portions of the bottom bearing surface33of the male casting. Referring toFIGS. 14-16, in a preferred embodiment, an automatic welding device818is applied to the fixture shaft814of the fixture800to rebuild the bottom bearing surface with weld. An exemplary welding device includes the AUTOBORE WELDER supplied by CLIMAX PORTABLE MACHINING & WELDING SYSTEMS, INC. of Newberg, Oreg. Of course, a number of other welding devices may be utilized without departing from the scope of the present invention.

The welding device818includes a torch assembly820and a bore welding assembly822. The torch assembly820includes a torch nozzle824and a spindle826for attachment to the bore welding assembly822. The spindle826is a component of a radial face torch. While any suitable radial face torch may be used, in a preferred embodiment the radial face torch is a BORTECH model A1035 Radial Face Torch Assembly provided by BORTECH CORPORATION of Keene, N.H.

The bore welding822assembly includes a control unit828and a welding facing head830. The control unit828starts and stops the weld process. It includes a control unit shaft832that extends upwardly from the control unit, a welding cam834located on the control unit shaft, and a roller switch836that, as explained further below, is engaged by the welding cam834as it rotates on the control unit shaft832when the welding device818is in operation. Referring toFIGS. 16 and 17, the welding cam834includes a series of small detents838so that when a detent838passes by the roller switch836, the roller switch836will no longer be engaged such that the torch nozzle824will cease its welding operation. However, the welding device818will continue rotating due to the continued operation of the welding facing head830. When a portion of the welding cam834not having a detent838engages the rolling switch836, the welding will restart. This allows for the intermittent, automatic welding of the bottom bearing surface of the male casting. While in a preferred embodiment there are 6 detents equally spaced apart along the circumference of the welding cam which allows for 15 degrees each of welding interruption, in other embodiments a different amount of detents may be used, or none at all

The welding facing head830controls the rotation and movement of the welding device818. It engages with the control unit shaft832and, when the welding device is ready for use, the welding facing head is able to rotate 360 degrees during the welding operation.

The bore welding assembly822also includes a connecting beam assembly840that at one end822attaches to the facing head and at the other end844is connected to the control unit828, which forms a connection between the fixture shaft814of the welding fixture and the connecting beam assembly840.

To perform the welding operation554, the welding fixture800is attached to the male casting10so that the forward end28of the male casting10faces the support plate802. The knobs810located on the side arms808and support plate802may then be rotated so that their respective screws812engage with the male casting to secure the welding fixture800to the casting10. Notably, as the screws812are tightened, the catch plate806will further engage with the inner surface of the anterior surface54of the male casting opening.

The control unit828is attached to the fixture shaft814of the welding fixture and the torch assembly820is passed through the cutout816in the base plate804from the underside of the casting10. The spindle826of the torch assembly820is then connected to the bore welding assembly822. Referring toFIG. 18, the torch assembly820is adjusted so that the torch nozzle824is positioned along an outer portion824of the bottom bearing surface33of the male casting10. Alternatively, the torch nozzle824may be positioned at an inside portion of the bottom bearing surface33of the male casting10.

The welding cam834should be rotated so that one of the detents838is positioned towards the posterior surface70of the opening. The male casting should be preheated as described above and maintained at 300°-500° F. throughout the welding process. This is accomplished through the use of an insulating blanket or an equivalent means. The male casting10is reheated as required in order to maintain the proper temperature. By actuating the control unit828, e.g., with a pushbutton, the welding process may then begin. The welding device will begin to apply the weld at an outer portion of the bottom bearing surface and, as rotation continues, the torch nozzle will rotate inwardly along the bottom bearing surface in a counter-clockwise direction as observed from the top of the casting. Typically, the torch nozzle will make between 10 to 12 passes or revolutions around the bottom bearing surface to apply one layer of weld. Typically, 4-8 layers of weld can be expected to “rebuild” the bottom bearing surface, although the actual number may vary depending on the amount of wear and the desired thickness of the weld. Moreover, preferably the gas used with the welding device will be either 100 percent CO2or a composition of 75% AR 25% CO2, although other compositions known to those in the art may be used.

As noted above, the presence of the weld cam834will cause an interrupted weld pattern to form on the bottom bearing surface. The roller switch836of the control unit will disengage when a detent838on the weld cam passes over it. This will cause the torch nozzle824to stop “welding” until the weld cam again actuates the roller switch. In a preferred embodiment, and as shown inFIG. 19, the weld pattern will be approximately 45 degrees of weld material848followed by approximately 15 degrees of no weld850. When the automatic welding operation is finished, the amount of weld may be measured with a gage to determine if the weld build-up is satisfactory. If the amount is deemed insufficient, the above process may be repeated, with the number of layers applied adjusted accordingly.

The welding device may then be removed from the welding fixture. The areas on the bottom bearing surface having no weld may then be manually “filled in” with weld. Using the same type of gas, the manually-applied weld may be added in the areas850that remain free of weld after the automatic welding process. These areas are blended with the automatically applied weld so that the entire bottom bearing surface has been built-up for the machining operation as described below. Notably, the automatic application of the weld material reduces the time an operator is required to weld the bottom bearing surface. Moreover, because this operation allows the weld to be applied from beneath the casting, it also limits any lengthy, awkward manipulation required by the operator, and does not necessitate inversion of the car or casting to perform the welding operation.

After the bottom bearing surface has had the weld applied, it should be allowed to slow cool557before proceeding to the machining operation. Desirably, while the welding fixture is still mounted to the casting, the casting will have an insulating box852, insulating blankets, and/or equivalent means applied to it (FIG. 20) to control the cooling rate of the casting. The insulating box is a two-piece box whose exterior is made out of sheet metal. The insulating box facilitates the cooling of the casting in a measured manner. Otherwise, if the casting cools too quickly, weld material may form cracks or develop other surface failures. The insulating box includes a pair of oppositely situated doors854. The doors854may be either fully opened or fully closed to control the exposure of the casting to ambient air during cooling. Moreover, any portions of the casting that remain exposed, such as due to the presence of any cutouts in the insulating box852, may be wrapped in an insulating blanket858.

Once the casting has cooled and the insulating box, blankets and fixture have been removed, the casting is mounted556and aligned558in the machining fixture200so that the machining operation560may be performed. As described above, this may include facing, grinding or milling, amongst other suitable operations, in order to remove excess weld to a specified dimension. Referring toFIGS. 6-11, in this semi-automatic method of the present invention, a boring bar assembly400, facing head assembly500, and facing head feed control600are used. The boring bar assembly400drives the facing head assembly500, which includes a machining tool502(FIG. 11), while the feed control600provides for the axial feed of the machining tool as welding material is being removed from the bottom bearing surface33of the male portion10of the casting, and provides for the adjustment of the feed rate of the machining tool502during the machining process. In a preferred embodiment, the facing head assembly500, boring bar assembly400and facing head feed control600are manufactured by CLIMAX PORTABLE MACHINING % WELDING SYSTEMS, INC. of Newberg, Oreg. Of course, other boring bar and facing head assemblies and/or facing head feed controls may be utilized without departing from the scope of the present invention.

Referring toFIG. 6, the boring bar assembly400includes an axial feed assembly402, a rotational drive assembly404, lead screw406, boring bar408, a plurality of clamp collars410a-cand a clamp ring412. As explained further below, the boring bar assembly400is affixed to the fixture by the insertion of the boring bar408into the bearing in the first opening206of the top plate202. Notably, the axial feed assembly402provides for the adjustment and movement of the boring bar408in a vertical direction through its engagement with the lead screw406. The rotational drive assembly404includes a motor405and rotational drive unit407that together drive and provide for the rotation of the boring bar408. In addition to the machining tool502, the facing head assembly500includes a facing head504, and a facing head carriage506. As described below, the facing head assembly500is connected to the boring bar408and thus rotates when the boring bar408is being driven by the rotational drive assembly404. The facing head assembly500retains the machining tool502that machines the bottom bearing surface33of the casting10. The facing head feed control600is in mechanical contact with the facing head assembly500and controls the feed rate, i.e., the rate the cutting tool moves or is “fed” in an inward direction along the bottom bearing surface as weld material is removed. It includes a feed adjustment602and jam wheel604. The jam wheel604locks the feed adjustment602into place. When the jam wheel604is loosened, the feed adjustment602may be adjusted to change the feed rate of the machining tool502.

To perform the machining operation, the boring bar assembly400is positioned above the fixture200applied to the casting10. As part of the boring bar assembly400, clamps410aand410bare secured to the boring bar408to prevent the boring bar408from falling out of the axial feed assembly402and rotational drive unit407when positioning the boring bar assembly400. The boring bar408is inserted into the first bearing238in the top plate202, completely through the first opening206and completely through the male casting opening32. However, clearance should be left above the second bearing240in the bottom plate204sufficient to position the facing head assembly500upwardly onto the boring bar408. Following the facing head assembly is a clamp collar508a, the facing head feed control600, and another clamp collar508b. Thereafter, the end414of the boring bar408is positioned through the second bearing240until the boring bar assembly clamp ring412covers the first bearing238. The clamp ring412is then secured over the first bearing238, such as through the use of a push-button, spring-loaded lock.

The machining tool502is also positioned by first determining the lowermost point of the material on the bottom bearing surface33to be machined. As shown inFIG. 9, the gauge bar232is positioned so that a primary flat side232a(FIG. 10) is horizontal across the support bars228. Then, such as through the use of a scale or tape measure, the location of the lowermost point from the flat side232of the gauge bar to the material requiring machining on the bottom bearing surface33is assessed and marked. Other methods may also apply.

The machining tool502is positioned in the tool holder carriage506and secured. As noted above, the tool may be a facing or similar cutting tool to facilitate the removal of weld material. The facing head assembly500is slid upwards on the boring bar408until the tip502aof the cutting tool502is positioned close to the lowermost location of weld material on the bottom bearing surface33, preferably within ¼ inch. The facing head assembly500is securely fastened to the boring bar408. The clamping collar508ais slid into direct contact with the underside501of the facing head assembly500and fastened to the boring bar408. The facing head feed control600is positioned loosely against the clamping collar508. Another clamping collar508bis slid upwards into direct contact with the underside606of the facing head feed control600and securely fastened to the boring bar408.

The remainder of the set up provides for “fine tuning.” The tolerances provided below are exemplary, and other tolerances may be used depending on machining requirements. The axial feed402includes a crank416that can be manually engaged to move the boring bar408upwardly so that the tip502aof the tool502comes within about 0.030 inches of a material low point of the area to be machined. The crank416thereafter is engaged downward for about one-half turn or 0.050 inches. The facing head also includes a pair of carriage control knobs508, one of which can be engaged to position the outboard end506aof the tool holder carriage506at a desired distance from the end503of the facing head. The tool holder carriage506are secured into place so it does not move. In one preferred embodiment, a pin and detent configuration may be used so that the carriage control knob “locks” the tool holder carriage506into place.

The facing head assembly500and machining tool502are rotated to the rear of the casting by engaging the rotational drive system404, such as through a pushbutton (not shown). Once the facing head assembly500is in position, the rotational drive system404is disengaged. The crank416of the axial feed402is then engaged for about one full turn so that the boring bar408moves upwardly about 0.100 inches towards the area to be machined. Clamp410cis then secured and the crank416of the axial feed402is disengaged. In one preferred embodiment, the crank has pins that engage with detents associated with the axial feed, so that when the pins are disengaged the axial feed is locked into place. Once ready to begin the actual machining, the boring bar408is engaged by depressing the push button, which results in the rotational movement of the facing head assembly500. If the above settings are incorporated, approximately 0.020 inches of material will be removed from the bottom bearing surface. However, as noted above, this embodiment is exemplary, and other settings may be used so that a greater or lesser amount of material is removed.

Advantageously, an operator may monitor the machining process without having to perform it, which as described above may require operator to either grind the bottom bearing surface from underneath the casting, or else require that the casting (and potentially the railcar) be inverted. Each of these techniques requires large amounts of time and are undesirable because the former requires a lengthy, awkward manipulation by the operator while the latter requires the manipulation of large equipment (casting and/or railcar). Moreover, articulated connectors are not suited for such removal from the railcar since they are integral to the car and such repair would be inefficient, time consuming, and expensive.

In a preferred embodiment, during machining it is desirable to feed the tool holder and carriage506inwardly along the bottom bearing surface approximately 0.010 inches per revolution of the machining tool502. Feed adjustment may be made by loosening the jam wheel604and turning the feed adjustment602in the appropriate direction. In this embodiment, counter-clockwise rotation of the feed adjustment602decreases feed, while clockwise rotation of the feed adjustment increases feed. If the feed is unknown, an initial slower setting may be used until the desired feed is achieved, at which time the jam wheel604may be resecured.

Moreover, metal chips700(FIG. 9) created by the machining process may need to be removed during the machining process. One way to accomplish chip removal is through the use of a low-pressure hose to blow chips away.

Once machining is complete, the equipment may be disengaged to determine whether the desired casting dimension has been achieved, i.e., the casting undergoes qualification562. In a preferred embodiment, this will occur after one pass along the bottom bearing surface by the cutting tool502. However, in the majority of cases, more than one pass will be necessary. The uppermost clamp collar410cat the top of the boring bar408is loosened and the crank416moves the boring bar408downwardly so that the cutting tool is moved in a downward direction away from the bottom bearing surface. As such, the facing head assembly500is moved so it is not in the way during qualification. The gauge bar232is positioned on the support bars228so that the primary flat side232ais vertical. In a preferred embodiment, if the gauge bar232can be slid under the machined casting surface and the clearance between the gauge bar and the machined surface is within 1/16 inches, then the desired dimension has been achieved. Additionally, it may be desirable to have the cumulative total of the non-machined areas of the bottom bearing surface not be greater than approximately one inch in diameter. If these tolerances are not satisfied, the process described above may be repeated, except that the boring bar crank416may be turned further to raise the facing head assembly500towards the bottom bearing surface so that additional material is removed. Upon completion of machining, sharp edges of the bottom bearing surface are ground with a radius of about 1/16″-⅛″ and remaining weld buildup is blended to the existing adjacent casting surfaces. The restored surface is then checked for defects.

Reconditioning Through the Use of Wear Plates

This alternate method does not require the application of a built-up weld followed by grinding, as described above. Referring toFIG. 12, a wear plate900instead may be welded or mechanically attached to a wear surface901of the male casting that has been machined or ground flat using processes like those noted above. The wear surface will be prepared as described above (e.g., machined, ground, burrs are removed, etc.) so that it is prepared to have a wear plate welded to it. By way of example, as to the bottom bearing surface33, the bottom bearing surface itself will act as the surface to which the wear plate is welded.

The wear plate may include a substrate layer904and a welded layer902(shown in exaggerated form inFIGS. 12, 12a, and12b). The substrate layer904is typically made of a weldable material and is the layer that is welded for attachment to the bottom bearing surface33. One suitable material is a weldable steel substrate, while in other embodiments, a low carbon or high-strength low-alloy steel may be used. The welded layer902acts in place of the built-up weld material described previously. The surface906of the welded layer will come in contact with the spherical ring surface25when the male casting10is inserted into the female casting12. Prior to attachment of a wear plate, the bottom bearing surface may be machined using the techniques described above until the desired casting dimension is achieved, which can be determined by measuring the casting with a gage. Preferably, the weld layer902of the wear plate900is made from chromium carbide, although other suitable materials may be used such as hard-facing weld material. Other options for the wear plate include, without limitation, wear plates case or flame hardened or having had other resistant surface treatments. Wear plates made completely out of materials like those noted for the substrate layer are also an option. The wear plate could also be comprised of stainless steel.

Accordingly, the casting may be reconditioned at a faster rate since the weld does not have to be built up. Rather, the wear plate needs only to be attached to the prepared wear surface. Notably, this procedure also may be used to recondition the bottom bearing surface3000of the female casting. Many alternative embodiments of the wear plate described herein are envisioned. For example, the opening950in the wear plate900may be concentric to the outside edge952of the wear plate900as shown inFIG. 21. Alternatively, as shown inFIG. 22, the opening950in the wear plate900can have an offset, or non-concentric relationship to the outside edge952of the wear plate900. In another alternative embodiment, the outside edge952of the wear plate900is not circular, rather it has cut-out portions. Other shapes are also envisioned.

Of course, one skilled in the art will realize that the machines, fixtures, tools and gauges used in the above embodiment of the reconditioning method are only exemplary and many alternatives exist. The examples illustrated herein are therefore not meant to be restricting. Moreover, while the ASF male castings are described, as known to those of ordinary skill in the art, the methods and equipment described herein may readily be adapted to be applied to other types of male castings, such as, for example, from National Castings, as well as to female castings. If the methods herein are applied to female castings12, the bottom bearing (or spherical ring) surface3000may be reconditioned in this fashion.