Patent Publication Number: US-9403542-B2

Title: Rail car

Description:
BACKGROUND 
     This disclosure relates to an improved rail car. 
     Railcars have evolved from simple four-wheel, fixed axle vehicles to multi-axle vehicles having sophisticated trucks for significantly improved maneuverability. Such improvements have allowed railcars to move larger loads at greater speeds. One system used to move large loads is a Schnabel car. A Schnabel car uses a combination of trucks, load spreaders and span bolsters to distribute a load over an expanded portion of track. 
     One prior Schnabel car utilized a rail car freight car having twelve axles. The arrangement specifically utilized two span bolsters each with three 2-axle trucks rotatably mounted on each span bolster. Such arrangement improved dynamic performance on curved track sections, however, having three rotatable points on each span bolster can provide some unpredictability in load movement on track curves. 
     As such it would be useful to have an improved rail car. 
     SUMMARY 
     The following disclosure relates to a rail car. In one embodiment, a railcar can comprise a span bolster, outer truck assemblies, and a middle truck assembly. The outer truck assemblies can be rotatably mounted to each end of the span bolster. The middle truck assembly can be slidably mounted at a middle portion of said span bolster. 
     In another embodiment, a railcar system can comprise a pair of railcars and a body. The rail cars can comprise a span bolster, outer truck assemblies, and a middle truck assembly. The outer truck assemblies can be rotatably mounted to each end of the span bolster. The middle truck assembly can be slidably mounted at a middle portion of said span bolster. The body can have two ends, each of the ends connected to one of the span bolsters. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates railcar system on a railway. 
         FIG. 2  illustrates a railcar comprising a truck body, a pair of span bolsters, and a plurality of truck assemblies. 
         FIG. 3  illustrates a span bolster that mounts to three 2-axle truck assemblies. 
         FIG. 4  illustrates a top view of a truck assemblies mounted on a span bolster. 
         FIG. 5A  illustrates an embodiment of a sliding assembly. 
         FIG. 5B  illustrates how an embodiment of a sliding assembly can be connected with a span bolster. 
         FIG. 6A  illustrates another embodiment of a sliding assembly. 
         FIG. 6B  illustrates how another embodiment of sliding assembly can be connected with a span bolster. 
         FIG. 7A  illustrates a line representation of railcar  101  on railway  104 . 
         FIG. 7B  illustrates arrangement of truck assemblies on a curved track. 
         FIG. 7C  illustrates a top view of a horizontal slot. 
     
    
    
     DETAILED DESCRIPTION 
     Described herein is a system and method for an improved rail car. The following description is presented to enable any person skilled in the art to make and use the invention as claimed and is provided in the context of the particular examples discussed below, variations of which will be readily apparent to those skilled in the art. In the interest of clarity, not all features of an actual implementation are described in this specification. It will be appreciated that in the development of any such actual implementation (as in any development project), design decisions must be made to achieve the designers&#39; specific goals (e.g., compliance with system- and business-related constraints), and that these goals will vary from one implementation to another. It will also be appreciated that such development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the field of the appropriate art having the benefit of this disclosure. Accordingly, the claims appended hereto are not intended to be limited by the disclosed embodiments, but are to be accorded their widest scope consistent with the principles and features disclosed herein. 
       FIG. 1  illustrates a train  100 . Train  100  can comprise a plurality of railcars  101  and railcar system  102 . Railcar  101  can be any wheeled vehicle configured to move on railway  104 . Railcar system  102  can be a plurality of railcars  101  and other components coupled together. Train  100  can further comprise a powered vehicle  103 . Powered vehicle  103  can direct the movements of railcar system  102  and railcar as it moves on a railway  104 . Railcar system  102  can be powered or unpowered rail vehicle that can be coupled together and configured to operate on railway  104 . Railcar system  102  can be used to carry oversized loads. Railway  104  can provide a runway for train  100 . Railway  104  can comprise curves. 
       FIG. 2  illustrates a railcar system  102  comprising a plurality of railcars  101  and a truck body  201 . Railcar  101  can comprise a span bolster  202 , and a plurality of truck assemblies  203 . Truck body  201  can connect be a support structure that connects to multiple span bolsters  202 . In one embodiment, truck body  201  can be rotatably connected to span bolsters  202 . Span bolsters  202   a  and  202   b  can be mounted at the opposite ends of truck body  201 . 
       FIG. 3  illustrates railcar  101 . In a preferred embodiment, truck assemblies can be 2-axle. Span bolsters  202  can be a support structure that links truck assemblies  203 . As such, span bolsters  202  can allow each truck assembly  203  to move relative to the other, as discussed further below. Moreover, span bolsters  202  can allow each end of railcar system  102  to rotate at a common point. Additionally, span bolsters  202  can be utilized to distribute the weight of truck body  201  on each truck assemblies  203 . Truck assemblies  203  can be a device mounting span bolsters  202  that permit truck body  201  to be maneuvered within railway  104 . Truck assemblies  203  can be the base support of railcar  101 . 
       FIG. 4  illustrates a top view of truck assemblies  203 . This embodiment illustrates that truck assemblies  203 , each a comprising rotatable assembly  401  or a sliding assembly  402 . In this embodiment truck assembly  203   a  and truck assembly  203   c  positioned at the outer ends of span bolster  202   a  can employ rotatable assembly  401 . Truck assemblies  203  can comprise a center frame  400 . Rotatable assembly  401 , mounted to center frame  400 , can allow the rotational movements for truck assemblies  203  on both ends of span bolster  202   a . As such, truck assemblies  203   a  and  203   c  can be rotatably mounted at each end of span bolsters  202   a . Meanwhile, truck assembly  203   b  positioned at the middle of span bolster  202   a  can utilize sliding assembly  402 . Sliding assembly  402 , also mounted to center frame  400  can use a track and guide method configured to allow sideward movements for truck assembly  203   b.    
       FIG. 5A  illustrates an embodiment of sliding assembly  402 . In this embodiment, truck assembly  203   b  can comprise a shaft  501 . Shaft  501  can protrude upward from the middle portion of center frame  400 . Shaft  501  can be attached to center frame  400  through soldering, welding, cementing, cast together, or through any fasteners. 
     Span bolster  202  can comprise a plurality of bearing system  502  and a horizontal slot  503 . Bearing systems  502  can be placed at the opposite sides of span bolster  202 . In one embodiment, bearing systems  502  can be horizontally offset from horizontal slot  503 . In another embodiment, bearing systems  502  can be horizontally in line with horizontal slot  503 . Bearing system  502  can rotate in place, allowing for low friction movement of span bolster  202 . In one embodiment, horizontal slot  503  can protrude from the bottom surface of span bolster  202 . In such embodiment, bearing system  502  can be built into the protruding rim of horizontal slot  503 . In another embodiment, horizontal slot  503  can recede into the bottom surface of span bolster  202 , such that horizontal slot  503  is flush with the bottom surface of span bolster  202 . 
       FIG. 5B  illustrates how an embodiment of sliding assembly  402  can be connected with span bolster  202 . Span bolster  202  can mount on top of truck assembly  203  such that shaft  501  of truck assembly  203   b  can be inserted within horizontal slot  503 . Shaft  501  can extend upward into slot  503 , however the length of shaft shall be such that it does not hit the back of slot when bearings are resting on center frame  400 . In an embodiment where horizontal slot  503  protrudes, such protrusion can be shorter than bearing system  502  so as not to hit horizontal slot  503 . When horizontal slot  503  is flush, shaft  501  can be longer than bearing systems  502  so that it reaches inside horizontal slot  503 . 
       FIG. 6A  illustrates another embodiment of sliding assembly  402 . Truck assembly  203   b  can comprise horizontal slot  503  and/or bearing systems  502 . In one embodiment, horizontal slot  503  can recede into the middle of center frame  400 . As such, horizontal slot  503  can form a recessed portion within the middle section of center frame  400 . In another embodiment, horizontal slot  503  can protrude from center frame  400 . In this embodiment, side bearings  502  can be higher than the walls of horizontal slot  503 . Furthermore, horizontal slot  503  can be attached to center frame  400  through soldering, welding, cementing or through any fasteners. 
     In this embodiment, shaft  501  can be positioned at the center of span bolster  202   a  such that when span bolster  202   a  mounts on top of truck assembly  203   b , shaft  501  can be inserted within horizontal slot  503 . In an embodiment wherein horizontal slot  503  recedes truck assembly  203   b , shaft  501  attached to span bolster  202   a  can be higher than side bearings  502 . This is to allow shaft  501  be mated within horizontal slot  503 . In another embodiment wherein said horizontal slot  503  protrudes from truck assembly  203   b , shaft  501  can be shorter than side bearings  502 . Such embodiment ensures that span bolsters  202   a  can rest on side bearings  502  but still allowing shaft  501  mated within horizontal slot  503  of truck assembly  203   b.    
       FIG. 6B  illustrates how another embodiment of sliding assembly  402  can be connected with span bolster  202   a . The embodiments for sliding assembly  402  can be configured such that the outer end of shaft  501  does not reach the inner surface of horizontal slot  503 . This can prevent friction between shaft  501  and horizontal slot  503  therefore allowing shaft  503  to slide freely within horizontal slot  503 . Furthermore, side bearings  502  can allow span bolster  202   a  move relatively with truck assembly  203   b.    
       FIG. 7A  illustrates a line representation of railcar  101  on railway  104 . For any railway  104 , a railway commission or other governing body will dictate a minimum radius  702  for curve  701 . Points  703  represent the position of rotatable assembly  401 . Specifically, points  703  can be the axis wherein outer truck assemblies  203   a  and  203   c  can rotate relative to span bolster  202 . The line that connects points  703  represents the center of span bolster  202 . As span bolster  202  is a rigid body, the center of span bolster will deviate from curve  701 . In a scenario wherein railcar system  102  crosses a curved track  104  a horizontal deflection  705  that can be measured. Such horizontal deflection  705  is at its maximum at a center point  704  between points  703 . In an embodiment wherein shaft  501  attaches to span bolster  202 , center point  704  represents the center of shaft  501 . In an embodiment wherein span bolster  202  comprises horizontal slot  503 , center point  704  represents the center of horizontal slot. 
       FIG. 7B  illustrates arrangement of truck assemblies  203  on curved track  104 . Thus, horizontal deflection  705  represents minimum displacement room on each side of shaft  501  within horizontal slot  503  necessary for railcar  101  to pass along railway  104  having curve  701 . To ensure proper alignment of truck assembly  203   b , horizontal deflection  705  can be determined as r(1−cos(sin ^−1(x/r))), wherein r can represent the minimum allowable radius  702 , and x can represent half the distance between points  703 . From r(1−cos(sin ^−1(x/r))), it can be established that the horizontal deflection  705  can be at its largest when minimum allowable radius  702  is smallest. Similarly, it can be concluded that horizontal deflection  705  can be at its smallest when radius  702  is largest. 
       FIG. 7C  illustrates a top view of horizontal slot  503 . When railcar system  102  travels a straight track  103 , shaft  501  can rest at the middle of horizontal slot  503 . However, the width of horizontal slot  503  should be chosen such that shaft  501  has a displacement distance on each side equal to or greater than r(1−cos(sin ^−1(x/r))). Further, such displacement distance should be afforded horizontally to bearing systems  502 . Otherwise, sliding movement between span bolster  202  and truck assembly  203   b  can be limited. This is to prevent span bolster  202  from dislodging from truck assembly  203   b . Truck assembly  203   b  can employ a sliding assembly  402  since truck assembly  203   b  will typically be substantially orthogonal with curved track  104 . As such, no rotation is necessary for truck assembly  203   b.    
     In a preferred embodiment, sides of horizontal slot  503  and shaft  501  are flat, and shaft is sized such that its flat edges fit snuggly within horizontal slot  503 . Such embodiment can prevent rotational movement of truck assembly  203   b . Edges of shaft  501  can be rounded to reduce friction with the sides of horizontal slot  503 . 
     Various changes in the details of the illustrated operational methods are possible without departing from the scope of the following claims. Some embodiments may combine the activities described herein as being separate steps. Similarly, one or more of the described steps may be omitted, depending upon the specific operational environment the method is being implemented in. It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments may be used in combination with each other. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.”