Abstract:
An extended end-sill assembly for a railcar, which assembly is produced by mating a front-sill casting and back-sill casting having a transition region therebetween wherein the endsill includes a cast-in-place center plate, a support arrangement for a cushioning apparatus and a wide-mouthed end for greater lateral travel of the coupler shank arm, and such dual casting assembly is inapposite to present production of such endsill assemblies that require fabrication of numerous plates, pieces and braces.

Description:
BACKGROUND OF THE INVENTION 
     The present invention provides an end sill assembly for a railroad car. More specifically, an extended length end sill assembly is provided for a railcar, with a truck assembly deeply recessed from a railcar end. Further, two as-cast components are mated to provide the end-sill assembly, which assembly is then connected to the railcar center sill. The longitudinal axes of the first and second as-cast components are vertically offset from each other to accommodate the height of the truck assembly and the alignment of the juxtaposed couplers of adjacent railcars. 
     Historically the elongated end-sill assemblies for automobile-carrying railcars have been fabricated components due to the extreme length of the end-sill arrangement. The fabrication process was both tedious and expensive. Casting the components of the as-cast end-sill assemblies provides two cast elements, which are ready for mating assembly and securement. This mating assembly eliminates the necessity for the fabrication and assembly of large plate sections to manufacture an elongate end-sill assembly, thus saving fabrication time and labor costs, as well as reducing the amount of space required for final assembly, storage of plate materials and the avoidance of multiple welds, which require care and inspection to avoid cold welds, porosity or other critical manufacturing defects. The casting parameters are more easily controlled on a more consistent basis, thus the component dimensions are more consistently repeated for ease of joining with mating parts. 
     The noted two-component system also moves the integrally cast center-plate and truck bolster into closer proximity to each other, which increases the available lading capacity of the railcar. 
     There are several extant cast draft sills and one is noted in U.S. Pat. No. 4,252,068 to Nolan. This structure is built with a generally planar base and planar top wall. It includes a tapered transition element at its inboard end for mating with the center sill. A pocket with a supporting rib structure is cast into the inboard end to receive a center filler plate. This disclosed end sill is expected to be between three and four feet in length, which is generally the length-dimension range of disclosed end sill structures for freight railcars in the U.S. 
     Alternatively, U.S. Pat. No. 5,809,899 to Kaufhold et al. discloses a cast draft sill with an integrally cast wheel truck connection. In one embodiment of this disclosure, a center pin extends downward from the draft-sill bottom for mating engagement with a standard center plate of a truck bolster. 
     A third cast draft-sill is shown in U.S. Pat. No. 5,931,101 to Kaufhold et al., which teaches a light weight draft sill with an integrally cast center-plate. However, in this disclosure and the above-noted patent structures the draft sills are single cast units with a single longitudinal axis generally provided between an upper plane and a lower plane. None of the structures are designed to accommodate an elongate end-sill assembly. Further, there is no disclosure or teaching of an angled end-sill assembly, either as a fabrication or casting. 
     SUMMARY OF THE INVENTION 
     The present invention provides a two-component cast end-sill assembly for mating with a center sill of a freight railcar. The first and front cast component or sill includes a housing for a cushioning device and the coupler shank. This first cast component has a longitudinal axis generally parallel to the longitudinal axis of the center sill. The back and second cast component of the end-sill assembly is mated to the center sill and has its longitudinal axis generally in alignment with the longitudinal axis of the railcar center sill. The elongated end-sill assembly is especially adaptable to automobile-carrier railcars where the lower longitudinal axis of the back sill permits added lading capacity while the front sill permits the coupler and cushioning devices to function in their normal modes of operation. The undercarriage truck assembly in these automobile carriers is displaced at an extended distance from the railcar ends, which requires use of the elongated end-sill assemblies and the long-shank couplers. The present assembly allows the use of the bell-mouth or wide-mouth front-sill to accept the long-shank coupler and permit adequate lateral motion of the coupler shank during railcar operation. In addition, the placement of the supporting rib structures allows expeditious mounting of the body bolster to the back sill, and the integral center plate assembly provides the mating center plate with a reduction in weight to the overall end-sill assembly, which weight reduction permits added railcar lading capacity. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     In the figures of the Drawing, like reference numerals identify like components, and in the Drawing: 
     FIG. 1 is an oblique top view of the deck, center sill and end-sill assembly of a vehicle carrier railcar; 
     FIG. 1A is the railcar structure of FIG. 1 noting only the center sill, the end-sill assemblies and the deck support cross-beams extending from the center-sill; 
     FIG. 2 is an enlarged view of one end of the railcar structure of FIG. 1; 
     FIG. 3 is a bottom view of the railcar structure of FIG. 2; 
     FIG. 4 is a longitudinal cross-section of the assembled end-sill assembly taken along line  4 — 4  in FIG. 5; 
     FIG. 5 is a plan view of the end-sill assembly of FIG. 4 in partial section; 
     FIG. 6 illustrates in cross-section a single-longitudinal-axis, prior art end-sill for a typical freight railcar; 
     FIG. 7 is a bottom view of a prior art end sill in position relative to the frame of a typical freight railcar; 
     FIG. 8 illustrates a prior art railcar truck assembly in an oblique view; 
     FIG. 9 illustrates an exemplary freight railcar with an endsill and truck assembly; 
     FIG. 10 is an exemplary illustration of an automobile carrier freight car with the railcar ends extending significantly beyond the truck assemblies at either car end; 
     FIG. 11 is a second exemplary illustration of an automobile carrier freight car with the railcar ends extending significantly beyond the truck assemblies at either car end; 
     FIG. 12 is an enlarged plan view of the front-sill casting in partial section; 
     FIG. 12A is a cross-sectional view of the front-sill casting in FIG. 12 taken along the line  12 — 12 ; 
     FIG. 13 is an enlarged plan view of the back-sill casting in partial section; and, 
     FIG. 13A is a cross-sectional view of the back-sill casting in FIG. 13 taken along the line  13 — 13 . 
    
    
     DETAILED DESCRIPTION 
     The present invention provides an elongated end-sill assembly  10  as noted in FIGS. 1 to  5 , which assembly  10  finds particular application in freight railcars noted as auto carriers or standard flat cars (not shown). Exemplary auto-carrier railcars  222  and  224  are shown in FIGS. 10 and 11. In these auto-carrier railcars  222  and  224 , the truck assembly is displaced at an extended distance from the car end in comparison to a typical gondola or boxcar type railcar  200 , which is noted in FIG.  9 . The term elongated refers to the length of end-sill assembly  10  in comparison to the typical end-sill assembly  220  for such gondola, boxcar or coal carrier railcar  200 . As shown in FIG. 9, truck assembly  210  is in relatively close proximity to railcar end  202 , thus avoiding the requirement for an elongated sill assembly  10 . Exemplary automobile carriers  222  and  224  respectively illustrate a railcar to accommodate compact vehicles and a railcar intended to accommodate full-size vehicles as published in Car and Locomotive Cyclopedia (1974). In both FIGS. 10 and 11, truck assemblies  210  are significantly further displaced from the car ends  216  than is truck assembly  210  in FIG.  9 . 
     Truck assembly  210  in FIG. 8 is an oblique view of an illustrative railcar truck assembly. Truck assembly  210  has first and second sideframes  230  and  232 , as well as four wheels  240 ,  242 ,  244  and  246  mounted at axle ends. In FIG. 8, bolster  212  has a bolster center plate  214  to receive a car body center plate for relative rotation between the mating center plates. The bolster plate center is approximately five feet from the car end in the typical freight car assembly of FIG. 9, which dimension is noted in the cited Car and Locomotive Cyclopedia (1974) at pages S3-85 and S3-86 for representative freight railcars. This arrangement of railcar  200  and truck assembly  210  is a typical assembly for the mounting of a railcar  200 , and more specifically its center sill, onto a railcar truck assembly  210 . However, the distance from the car end to the bolster center plate in autocarriers  222  and  224  of FIGS. 10 and 11 are almost twelve feet from the railcar end  216 . Thus provision of an end sill assembly  10  for such elongated members has been accommodated by metal fabrication of plate materials meticulously assembled and welded in frames and jigs to produce an acceptable endsill assembly. However, such fabrication is labor intensive and time consuming to provide reproducible results and parts. Thus, it is desired to provide a cast product with a finished shape where possible as the molds for such castings can be readily reproduced and the machining or labor input after casting is considered to be nominal. 
     The present invention provides an elongated endsill assembly  10  for autocarrier railcars  222  and  224 . More particularly, assembly  10  in FIGS. 4 and 5 has front sill  12  and back sill  14 , which are mated and secured at junction  16 . Securing of mated front sill  12  and back sill  14  can be accommodated by means known in the art such as welding, brazing, soldering or riveting for example. These are merely examples and not limitations. In the prior art illustrations of FIGS. 10 and 11, car body center sill  218  includes a sloped portion  226  for mating with endsills  220  inboard of truck assemblies  210 . However, the present autocarrier railcars  222  and  224  have the tapered or sloped region  226  outboard or forward of truck assembly  210 . This car structure change was noted to increase the lading capacity and must now be accommodated by the structure of endsill assembly  10  for both shape and load bearing capability. 
     In FIGS. 4 and 5, front sill  12  of endsill assembly  10  has forward end  20 , rearward end  22 , and longitudinal axis  23 . Front sill  12  is more clearly shown in FIGS. 12 and 12A in enlarged views. In these figures, front sill  12  has longitudinal axis  23 , first sidewall  30 , second sidewall  40 , top wall  50  and cavity  60 . Front sill  12  is approximately two-thirds of the net length of endsill assembly  10 , which is only noted for consideration of proportion in this description and not as a limitation. First sidewall  30  has parallel segment  31 , and laterally extending flange  32  with a plurality of apertures  34  along the length of front sill  12 . Second sidewall  40  has parallel segment  41 , and laterally extending flange  42  with a plurality of apertures  34  the length of front sill  12 . First sidewall segment  31  and second sidewall segment  41  are generally parallel and are connected by top wall  50  with cavity  60  open at lower edge  62 . Each of sidewalls  30  and  40  have multiple vertical reinforcing ribs  33 ,  35  and  37  along flanges  32  and  42 , respectively, which ribs  33 ,  35  and  37  are sloped between sidewalls  30 ,  40  and flanges  32 ,  42 . Alternatively, assembly  10  may be provided without ribs  33 ,  35  and  37  for mating with a railcar. 
     Forward end  20  is flared and has a first width  70 , which is greater than second width  72  between first sidewall sement  31  and second sidewall segment  41 . First sidewall  30  has first tapered segment  36  extending from forward end  20  to intersect parallell sidewall segment  31  at first intersection  84 . Similarly, second sidewall  40  has second tapered segment  46  extending from forward end  20  to intersect second parallel segment  4 l at second intersection  86 . The tapered segments  36 ,  46  provide a bell or wide-mouth opening  74  at forward end  20  to accommodate a greater degree of lateral displacement to coupler  76  noted in FIGS. 4 and 5, which promotes greater safety for curves and less wear on the sidewalls  36 ,  46  from contact with coupler shank  78 . 
     First front stop  80  and second front stop  82  in cavity  60  are integrally cast at respective first and second sidewall intersections  84  and  86 . Front stops  80  and  82  are mechanical stops for the travel of cushioning unit  100  or, more specifically, its pocket casting  101  in FIGS. 4 and 5, which provides mechanical grounding for unit  100  in the draft direction of travel of railcars  222 ,  224 . 
     In proximity to back end  22  in FIGS. 4,  5 ,  12 , and  12 A, first boss  90  is provided on first sidewall  30  and second boss  92  is provided on second sidewall  40 . First boss  90  has slot  94  and second boss  92  has second slot  96 , which slots  94 ,  96  are open to cavity  60  and in a facing alignment. Slots  94  and  96  are operable to receive a mounting bracket from a cushioning unit, such as unit  100  in FIGS. 4 and 5. Mounting slots  94 ,  96  provide a securing position for cushioning unit  100  and allow sliding engagement of its pocket casting for contact with front stops  80  and  82  during travel of the railcar in the draft direction. In addition, cushioning unit  100  is operable to absorb buff direction loads transferred through arm  102  in cavity  60  as unit  100  is secured in position in cavity  60  at slots  94  and  96 . The specific type or style of cushioning unit  100  is not a limitation to the present invention, and the noted structure is merely exemplary. 
     In FIG. 4, coupler shank  78  is secured to pocket casting  101  of cushioning unit  100  by pin  99 , which is a connection method known in the art. Further, it also known to connect a coupler and its shank to an endsill with a key, but the specific connecting means between cushioning unit  100 , its pocket casting  101  and coupler shank  78  is not a limitation to the present invention. 
     As noted in FIGS. 4 and 12A, front sill  12  has transition region  75  with upper wall  50 , sidewalls  30  and  40 , and flanges  32  and  42  downwardly tapered generally between first and second bosses  90  and  92 . The specific angle of the taper or slope of these structural walls is adequate to accommodate the necessity to provide rear opening  25  in alignment to receive back sill  14 . More particularly, it is noted in FIGS. 4 and 12A that top wall  50  initiates its taper forward of first and second bosses  90  and  92 , but flanges  32  and  42  only taper from the back of bosses  90  and  92 , which is the design necessity for coping with the difference in height of sidewalls  30  and  40 . Sidewalls  30  and  40  are similarly tapered to meet back opening  25 . In addition, back opening  25  has a narrow internal land or perimeter  27 , which is generally parallel to longitudinal axis  23  to accommodate mating with back sill  14 . Although transition region  75  is noted as integral with back end  22  of front sill  12 , it is considered that transition region  75  could be cast at forward end  120  of back sill  14  to mate with front sill  12 . A further, alternative structure could, if required, provide transition region  75  as an independent cast structure for mating with forward end  120  and back end  22  of cast back sill  14  and front sill  12 , respectively. 
     Back sill  14  in FIGS. 4,  5 ,  13  and  13 A is generally a straight casting with longitudinal axis  110 , forward end  120 , rearward end  122 , upper wall  112 , lower edge  124 , first sidewall  114 , second sidewall  116  and a cast-in-place center plate  118  for mating with a bolster center plate, such as bolster center plate  214  in FIG.  8 . Back-sill longitudinal axis  110  is vertically displaced downward from front-sill longitudinal axis  23 , which change in vertical position is accommodated by tapered transition region  75  of front sill  12  to thus provide assembly  10  after mating of back-sill  14  and front-sill  12 . 
     First back-sill sidewall  114  in FIGS. 5 and 13 has a lower flange  126  along the length of back-sill lower edge  124 . Similarly, second back-sill sidewall  116  has lower flange  128  extending the length of back sill  14  at lower edge  124 . In addition, first and second sidewall  114  and  116  each have respective upper flanges, however, only upper flange  130  along sidewall  114  at upper wall  112  is shown, but a similar upper flange is provided along sidewall  116  at upper wall  112 . Upper flanges  130  extend about an equidistant longitudinal length along sidewalls  114 ,  116  on either side of center plate  118 . Back sill  14  has chamber  138 , which is generally open at lower edge  124 , but center plate  118  partially occupies at least a portion of the volume of chamber  138  and thus partially encloses chamber  138 . Vertical outer reinforcing ribs  141  and  143  are provided on each sidewall  114  and  116 , which ribs  141 , 143  are utilized to locate or position the body bolsters coupled to back-sill  14  at assembly to a railcar. 
     Center plate  118  is illustrated as an annulus protruding below lower edge  124 . However, center plate  118  has vertical support ribs  119  extending between lower edge  124  and upper wall  112  in chamber  138 . In addition, horizontal support rib or disc  121  extends between first sidewall  114  and second sidewall  116  approximately midway the distance between lower edge  124  and upper wall  112  in chamber  138 . Aperture  123  extends through bolster center plate  118 , and appears in plan view as a continuous bore or passage extending through upper wall  112 . In addition, center plate  118  has bottom plate  117  at lower edge  124  extending between first and second sidewalls  114  and  116 . 
     Forward end  120  of back sill  14  has a flared or compressed structure terminating in a flat land  140 , which is noted as extending about the perimeter of back sill  14 , which flared structure appears to telescope from back sill  14  for mating with land perimeter  27  of front-sill back-end  22  at opening  25 . Rearward end  122  of back sill  14  also has a flared portion with telescoping land perimeter  144  for mating with the railcar body center sill  146 , which is noted in FIGS. 1 and 1A. 
     At mating of back-sill land  140  with front-sill land perimeter  27  the two cast elements, back sill  14  and front sill  12 , are joined to provide a single end sill casting  10 . The mated components provide a complex structure, elongate end sill  10 , from two castings front sill  12  and back sill  14  with nominal secondary operations. Securing of the two castings may be accommodated by means known in the art, such as welding. 
     Front sill  12  and back sill  14  are mated to provide endsill assembly  10 , which assembly  10  is mated with center sill  146  by the nesting of rear land  144  into center sill  146 . The junction of the connected center sill  146  and endsill assembly  10  junction may be secured by means such as weldments and a tie plate  160  noted in FIG.  3 . Further, crossbearers  162  and  164  of railcar  156  are noted in FIGS. 1A and 3 on either side of endsill assembly  10 . Crossbearer  162  extends from railcar side  166  and is secured to front-sill second sidewall  40  between reinforcing ribs  33  and  35 . Similar crossbearer  163  is provided to be secured between first sidewall  30  and railcar side  168 , and it is similarly secured between reinforcing ribs  33  and  35  on first sidewall  30  in the case where ribs  33  and  35  are present. Second crossbearer  164  extends from railcar side  166  to be coupled to second sidewall  40  generally in proximity to boss  92  and reinforcing rib  37 . Again a similar crossbearer  165  is provided from railcar side  168  for connection to endsill assembly  10  and first sidewall  30  in proximity to boss  90  and reinforcing rib  37 . It is understood that the crossbearers coupled to similar positions on first and second sidewalls  30  and  40  are generally aligned between the railcar sides  166  and  168 . First body bolster  180  extends from railcar side  166  and is secured to back-sill second sidewall  116  between ribs  141  and  143 . Second body bolster  182  extends from railcar side  168  and is secured to back-sill first sidewall  114  between ribs  141  and  143 . Body bolsters  180  and  182  are generally aligned and may be secured by means known in the art, such as welding. In FIG. 2, first cover plate  184  is secured onto first body bolster  180  and second-sidewall upper flange  130  generally in planar alignment with upper wall  112 . Similarly second cover plate  186  is secured onto second body bolster  182  and first-sidewall upper flange  130  generally in planar alignment with upper wall  112  and first cover plate  184 . 
     Front support plate  190  and rear support plate  192  for cushion unit  100  are secured to front-sill flanges  32  and  42  to secure cushion unit  100  in chamber  60 . Support plates  190  and  192  are secured to flanges  32  and  42  by means known in the art such as welding, brazing, riveting or other means. 
     As noted above, front-sill  12  and back-sill  14  are individually cast components, which do not require elaborate machining, individual jigs or fixtures. In endsill assembly  10 , longitudinal axis  110  of back-sill casting  14  is vertically lower than longitudinal axis  23  of front-sill casting  12 , although both axes are generally parallel to each other and the longitudinal axis of railcar  156 . Endsill assembly  10  is designed with these offset axes  23  and  110  to accommodate a railcar structure which allows more lading than previous railcar structures. The offset axes are accommodated by transition region  75  between back end  22  and bosses  90  and  92  of front-sill  12 . In this arrangement, front-sill casting provides the housing for installation and operation of cushioning unit  100  and coupler shank  78  at the correct vertical elevation for interchange service. Simultaneously, back sill casting  14  accommodates the lower level deck along railcar center sill  146 , and includes an integral body bolster center plate for mating with a truck assembly center plate, for example truck bolster center plate  214  in FIG.  8 . These two castings  12  and  14  require the usual post-casting operations to remove extraneous material such as sprues, risers and flashing, but they do not require precise alignment of individual sidewalls  30 ,  40 ,  114  and  116  as well as upper walls  50  and  112  in jigs and fixtures before welding long seams at contacting corners. Thus the threat of cold weld joints, weld porosity, heat affected zones, as well as other hazards coupled with such fabrication are avoided. As a result of avoiding the problems and costs associated with fabrication of individual panels to produce an endsill assembly, some of the benefits realized by casting and mating of only two components are labor savings, consistently reproduced castings for the final assemblies, and a reduction in the number and cost of jigs and fixtures. 
     In operation, endsill assembly  10  provides a housing for cushioning unit  100  and allows mating of coupler shank  78  with the pocket casting of unit  100  by pin  99 , as shown in FIGS. 4 and 5. The wide-mouthed end  20  of front-sill casting  12  and endsill assembly  10  allows significant lateral displacement of coupler shank  78 , which improves the operation of truck assembly  210  and railcar  156  through curves without potentially damaging impact of shank  78  against sidewalls  30  and  40 . 
     While only specific embodiments of the invention have been described and shown, it is apparent that various alterations and modifications can be made therein. It is, therefore, the intention in the appended claims to cover all such modifications and alterations as may fall within the scope and spirit of the invention.