Abstract:
A two-piece anchor assembly has a retainer and an interlocking link. The link is a unitary component that is formed by a single forging step. The link is secured to the floor of a railway flatcar by the retainer. A steel band is connected at one end to a load bearing surface of the link of a first anchor assembly and at another end to a load bearing surface of the link of a second anchor assembly. A tensile force is then applied to the steel banding and crimped with a clip in order to secure cargo. The load bearing surface has an enhanced banding radius, which reduces the risk of band breakage when the steel band is subjected to a high tensile force by preventing “creasing” at contact locations.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This is a continuation-in-part application of application Ser. No. 29/204,976, filed May 6, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     This invention generally relates to an anchor for securing cargo, using metal banding, onto railway cars including flatcars, center beams, gondolas and log cars. An assembly comprising an interlocking retainer and link is used to decrease the occurrence of banding breakage. The enhanced radius of the link provides a greater load bearing area for engaging the banding, thereby reducing the stress present in the banding when securing heavier and/or top-heavy loads, such as steel pipe. Special application is found for this approach in securing heavy loads transported by flatcar.  
         [0004]     2. Description of Related Art  
         [0005]     Heavy loads, such as steel pipe and the like, can be transported in a number of ways, including by flatcar. In order to prevent the cargo from becoming damaged, it is necessary to provide securing means. Various known securing means include plastic strapping, cord strapping, and steel banding. The preferred way to secure a heavy load is to bind it with a plurality of steel bands or straps. In practice, each band is connected to the floor or side frame of the flatcar by an anchor assembly at opposite sides of the cargo. Once the band is connected to the anchors and tightened, a crimp seal typically is applied to maintain an appropriate tension level during transport.  
         [0006]     Many types of anchor assemblies are well-known. The “Flexi” anchor assembly made by Ireco LLC is an example of a known device.  FIGS. 1-4  illustrate a device  20  according to the two-piece “Flexi” anchor assembly. The “Flexi” assembly  20  comprises a steel retainer  22  which is affixed to the floor or frame  24  of a flatcar and a steel link  26  which is movably connected to the retainer  22 . The arcuate retainer  22  takes the form of an inverted “U” which can be welded to the floor or frame  24  of the flatcar. The link  26  is triangular and defines a generally triangular central aperture  28  which interlocks the retainer  22 . The anchor assembly  20  is configured such that the retainer  22  passes through the central aperture  28  of the link  26  and effectively hooks the link  26  to a floor surface or a frame area  24  of the flatcar.  
         [0007]     One side  30  of the link  26  includes a banding portion  32 , while the end  34  defined by the intersection of the other two sides  36  engages the retainer  22 .  FIGS. 1 and 2  show that the banding portion  32  includes a lateral convex curvature surface  38  facing the central aperture  28 . This part of the banding portion  32  has a radius of curvature “R” of approximately five inches.  FIGS. 3 and 4  show that the cross section  40  of the retainer-engaging end  34  is circular, while the cross section  42  of the banding portion  32  approximates a rectangle with curved corners. The two corners  44  nearest the central aperture  28  have a 0.25 inch radius of curvature “r”.  
         [0008]     In use, a securing means, such as a steel band  46 , is passed through the aperture  28  of the link  26 , so as to engage the banding portion  32 . Banding surface  38  is sufficiently wide to accept a 1.25 inch or 2 inch steel band. When tension is applied to the steel band  46 , it tightens against the banding portion  32  and deforms in part to take the shape of the lateral convex curvature surface  38 .  FIG. 2  shows in broken lines that the link  26  is free to take an angled orientation when the steel band  46  engages the banding surface  38 .  FIG. 2  also shows in broken lines the use of a cable or wire  48  extending from an end of the link between two sides  30  and  36 .  
         [0009]     The steel band  46  engages a portion of the cross-sectional perimeter of the banding portion  32  of the link  26 , best shown in broken lines in  FIG. 3 . The surface of the banding portion  32  along the link  26  generally conforms to the opposing, parallel surfaces  50  of the link  26  and the lower surface  52 . The magnitude of the curvature of the steel band  46  about the banding portion  32  is referred to herein as the banding radius “r”. It can be seen that the banding radius “r” in  FIG. 3  varies due to the irregular shape of the banding portion  32 . The lower curved corners  44  each subject the steel band  46  to a relatively sharp curve, which can result in creasing of the steel band  46 .  FIG. 3  also shows the link  26  flat against the floor surface  24  of the flatcar, in a stored position when it is not in use.  
         [0010]     It will be appreciated that a large tensile force must be applied to the steel bands in order to secure the cargo. One problem associated with prior art anchor assemblies which we now have determined to be important is that, when the steel bands are subjected to such large tensile forces, especially when combined with forces that result from even slight shifting of lading weight during the rocking movement of rail transport, there is the possibility that metal fatigue will cause the bands to fail. The movement of rail transport can cause repetitive back and forth bending at locations where the banding engages a corner or tight radius.  
         [0011]     We have determined that the banding radius of anchor assemblies as illustrated in  FIGS. 1-4  is inadequate, especially when used to secure top-heavy or uneven loads, such as a load of steel pipes, the steel band can become creased along the curved corners of the banding portion, which creases are subjected to dynamic bending forces over time and subsequently break. This is especially problematic when the cargo must be transported a great distance. The steel band can withstand only a certain stress level and will deform and fail once that level is exceeded. It is thought that the critical stress level decreases due to the combination of creasing, dynamic bending forces, and metal fatigue associated with prior art anchor assemblies. As large tensile forces are required to safely secure heavier loads, and as heavy unbalanced loads need to be transported by rail over long distances, an anchor assembly which reduces the risk of band breakage is needed.  
         [0012]      FIGS. 5 and 6  illustrate examples of previous attempts to solve these band breakage problems. As shown, both anchors  56  and  58  provide a right cylindrical element  60  having a larger banding portion than that illustrated in  FIGS. 1-4 , while also providing an increased banding radius. The cylindrical element  60  is separate from the link body  62  and mounted thereto by a bolt  64 , which is itself secured to the link body  62  by a threaded nut  66 .  
         [0013]     It will be appreciated that, in lading anchors for steel bands, the stress in the steel band is inversely proportional to the area of the band which engages the banding portion of the link. Hence, for a given tensile force applied to the steel band, a larger area of engagement between the band and the banding portion of the anchor will allow for a greater force distribution, which decreases the stress to which the steel band is subjected. An increased banding radius (perpendicular to the axis of a right cylinder such as element  60  of  FIGS. 5 and 6 ) is also desirable because it reduces the risk of creasing the steel band which, when combined with dynamic bending forces, leads to metal fatigue and eventually failure at heavier loads. Accordingly, the anchor assemblies of  FIGS. 5 and 6  attempt to decrease band breakage by providing a larger banding portion and right cylindrical banding radius. The anchor assemblies of  FIGS. 5 and 6  are relatively expensive because they require several components (i.e. a cylinder, a bolt, and a nut) to achieve their goal.  
         [0014]     Accordingly, a general object and aspect of the present invention is to provide an improved anchor assembly for use with a railway car such as a flatcar, a center beam car, a gondola car, a log car and the like.  
         [0015]     Another object or aspect of this invention is to provide an improved anchor assembly which reduces the risk of band breakage for heavier loads and those having an unbalanced or high center of gravity without increasing the number of components of a current anchor assembly.  
         [0016]     Another object or aspect of the present invention is to provide an improved anchor assembly and method that address metal banding breakage problems for top-heavy lading loads, including those encountered during long-distance rail transport.  
         [0017]     Other aspects, objects and advantages of the present invention, including the various features used in various combinations, will be understood from the following description according to preferred embodiments of the present invention, taken in conjunction with the drawings in which certain specific features are shown.  
       SUMMARY OF THE INVENTION  
       [0018]     In accordance with the present invention, an anchor assembly reduces the risk of band breakage at large tensile forces by providing a link with a large load bearing surface having an enhanced banding portion configuration which decreases “creasing” of metal banding that is anchored by the assembly and decreases bending stress transmitted to the steel band at the anchor location during rail transport, even over long distances and with lading loads having a relatively high center of gravity.  
         [0019]     Notably, a steel link according to the present invention is made, typically by forging or casting, as a single component, in contrast to the multiple components used in the prior art anchor assemblies illustrated in  FIGS. 5 and 6 . It is estimated that a link according to the present invention costs approximately half as much, or less, to manufacture and assemble as the  FIGS. 5 and 6  links, while achieving performance characteristics at least as advantageous as those of FIGS.  5  or  6 . 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIG. 1  is a top plan view of a prior art anchor assembly in a stored position;  
         [0021]      FIG. 2  is a front elevational view of the anchor assembly of  FIG. 1 , with broken lines to illustrate the link-retainer connection and to show the application of a wire or a steel band;  
         [0022]      FIG. 3  is a right side cross-sectional view of the link of  FIG. 1 , with the retainer in elevation, showing the link in a stored position and a broken line illustration of a steel band applied to the link;  
         [0023]      FIG. 4  is a cross-sectional view of the link of the anchor assembly shown in  FIG. 1 ;  
         [0024]      FIG. 5  is a perspective view of another prior art anchor assembly having an increased banding radius;  
         [0025]      FIG. 6  is a front elevational view of a further prior art anchor assembly having an increased banding radius;  
         [0026]      FIG. 7  is a right side perspective view of an anchor assembly having an improved link according to the present invention;  
         [0027]      FIG. 8  is a front elevational view of the anchor assembly of  FIG. 7 , with broken lines to illustrate the link-retainer connection;  
         [0028]      FIG. 9  is a right side elevational view of the anchor assembly of  FIG. 7 ;  
         [0029]      FIG. 9A  is a right side cross-sectional view of the link of  FIG. 7 , with the retainer in elevation, showing the link in a stored position and a separate broken line illustration of the link in use;  
         [0030]      FIG. 10  is a top plan view of the anchor assembly as shown in  FIG. 8 ;  
         [0031]      FIG. 10A  is a top plan view of the anchor assembly as shown in  FIG. 8 , with an applied steel band;  
         [0032]      FIG. 11  is a bottom plan view of the anchor assembly as shown in  FIG. 8 ;  
         [0033]      FIG. 11A  is a bottom plan view of the anchor assembly of  FIG. 7 , with an applied steel band;  
         [0034]      FIG. 12  is a cross-sectional view of the improved link of  FIG. 7 , along the line  12 - 12  of  FIG. 8 ; and  
         [0035]      FIG. 13  illustrates a surface which may be rotated in order to define the shape of the large load bearing surface and optional guide flanges of the improved link of  FIG. 7 , along the line  13 - 13  of  FIG. 9 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention and virtually any appropriate manner.  
         [0037]      FIG. 7  shows an anchor assembly  68  having an improved link  70  according to the present invention. The anchor assembly  68  includes the retainer  22  of  FIG. 1 , which interlocks the improved link  70  according to the above description of the prior art anchor assembly  20 . The improved link  70  functions to receive metal banding in the general sense of the prior art link  26  of  FIG. 1 . However, as perhaps best illustrated in  FIG. 9A , the large load bearing surface  72  of link  70  is larger than the banding portion  32  and allows for a greater banding radius “rr”. Preferably, the surface  72  has a banding radius “rr” which is between approximately one-half inch and approximately one and one-half inches. In a preferred embodiment, this radius “rr” is on the order of about one inch.  FIG. 9A  shows that the large load bearing surface  72  has a cross-sectional area  76  which is substantially larger than the nominal cross-sectional area  40  of the link  70  at other points, such as at the retainer-engaging end  34 . In contrast,  FIG. 4  shows that the cross-sectional area  42  of the banding portion  32  of the prior art link  26  is comparable to the cross-sectional area  40  at the retainer-engaging end  34 .  
         [0038]      FIG. 9A  shows that the large load bearing surface  72  approximates a smooth arc along radius “rr”, whereas the banding portion  32  illustrated in  FIG. 3  is more U-shaped and creates isolated zones  44  with small banding radii “r”. Accordingly, due to the improved link  70  of the present invention, the tensile stress in the steel band  46  is spread over a greater surface area, there is a reduction in “creasing” along the radius “rr” when compared with along radii “r”, and the occurrence of band breakage at heavier and/or relatively unstable loads is decreased. Furthermore, it is thought that, under typical transport conditions, an improved link according to the present invention significantly reduces or virtually eliminates band breakage by limiting metal fatigue which, in prior art anchor assemblies, causes the critical stress level of the metal banding to drop below the amount resulting from the applied tensile force.  
         [0039]     In an alternate embodiment, the improved link  70  can include two guide flanges  78  which are shown disposed along the sides of the large load bearing surface  72 . The flanges  78  extend beyond or flank the large load bearing surface  72 , as best shown in  FIGS. 10 and 10 A, and guide the steel band  46  when it is first applied to the link  26 , by preventing it from moving laterally beyond the bounds of the large load bearing surface  72 .  
         [0040]     As shown in  FIG. 9A , in the stored position, the guide flanges  78  can be useful in preventing the large load bearing surface  72  from coming into contact with the floor surface  24  of the flatcar. Accordingly, the flanges  78  can assist in having the large load bearing surface  72  remain cleaner than when flanges are omitted and allow a true fit for the steel band  46 , when engaged. Also, unlike prior art links which will freeze to the railway car deck or frame under winter conditions, flanges  78  minimize the risk of such freezing, due largely to the minimal surface of the unit according to the invention that engages the deck or frame of the car.  
         [0041]     The improved link  70  may include a lateral, convex curvature  80  along the large load bearing surface  72 , in which event the curvature  80  will have a minimum radius “RR”. Radius “RR” can be substantially constant throughout the transverse curvature of radius “rr”.  FIG. 13  shows the shape of a surface  82  which may be rotated through an obtuse angle in order to form the large load bearing surface  72  and guide flanges  78  when lateral radius “RR” is substantially constant. The arc  84  corresponding to the large load bearing surface  72  preferably has a minimum radius of curvature “RR” of between approximately five and one-half inches and approximately fifteen inches along the surface  72 . More preferably, the minimum radius of curvature “RR” is within a range of approximately eight and approximately fourteen inches. A most preferred minimum radius of curvature “RR” is on the order of about ten inches.  
         [0042]     Alternatively, lateral radius “RR” can vary throughout some or all of the transverse curvature of radius “rr”. In such a situation, the minimum lateral radius “RR” noted above will occur at only some locations, or perhaps only one location, along the transverse radius “rr”. In a typical approach to providing a varying lateral curvature, the central lateral radius “RR” will exhibit such minimum radius, as shown in  FIG. 8  and  FIG. 13 . The lateral radius “RR” at other locations along the lateral curvature  80  will be greater than the minimum radius.  
         [0043]     As an illustration of a varying lateral radius “RR”, at the locations where transverse diameter “D” intersects the lateral surface of curvature  82 , such as at  86  in  FIG. 12 , the lateral radius “RR” is nominally infinite, with the lateral curvature at this location approaching or reaching a straight line. In this illustration, there is a gradual reduction in the respective lateral radii “RR” values between the minimum lateral radius location or radii locations and the straight-line or approximate straight-line lateral radius or radii. Thus, the value of lateral radius “RR” at intersections  90  is greater than the value of the lateral radius “RR” at mid-point intersection  88  and is less than the value of lateral radius “RR” at diameter intersections  86 . Substantially this same pattern of lateral radius “RR” values variation can vary in a gradually decreasing manner between intersections  90  and mid-point intersection  88  and in a gradually increasing manner between intersections  90  and diameter intersections  80 .  
         [0044]     When a sufficient tensile force is applied to the steel band  46 , it will beneficially deform to match the lateral curvature “RR” of the large load bearing surface  72 , which provides a “self-centering” function that prevents lateral shifting of the steel band  46  and helps secure the cargo. It will be seen that the radius of curvature of the transverse radius “RR” is preferably greater than the radius “R” of the prior art link, because an adequate “self-centering” function is achieved, with less deformation of the steel band  46  than with radius “R” of the link of  FIGS. 1-4 .  
         [0045]     In a preferred embodiment, the large load bearing surface  72  preferably defines a symmetrical arc. For example,  FIG. 12  shows that the large load bearing surface  72  can define an arc which extends above transverse diameter “D” and is greater than 180° and not more than 250°, preferably approximately 200°. However, a greater or lesser arc angle than that illustrated in  FIG. 12  or a non-symmetrical curve or arc are also contemplated by the present invention.  
         [0046]     In a preferred embodiment, the top of cross sectional area  76  (i.e. the two sloped surfaces closing the area generally above transverse diameter “D”) defines a symmetrical 166° angle. The exact shape of this portion is not critical, because it does not engage the steel banding in operation. As such, a complete cylindrical surface, such as  60  in  FIGS. 5 and 6  is unnecessary, because the steel band  46  will not engage much of the upper surface. Thus, a shape such as that illustrated in  FIG. 12  is preferred, because unnecessary material is avoided without degrading performance.  
         [0047]     Importantly, the improved link  70  is a unitary structure. A link  70  according to the present invention may be formed in a single drop forging step and there is no need for later assembly of separate parts. Such an integral construction also provides a very durable link which is less susceptible to breakage or unintended disassembly.  
       EXAMPLE  
       [0048]     In a long-distance road test of about 1,000 miles along a commercial rail route, a link according to the present invention was compared to the prior art link of  FIGS. 1-4  and the alternate retainer  22   a  which can be seen in  FIG. 5 . In the road test, three flatcars with thirty-six attachment points (i.e. eighteen steel bands) each were loaded with steel pipe according to Vibration Isolation Connection requirements of the American Association of Railroads (AAR).  
         [0049]     The first flatcar used prior art links according to  FIGS. 1-4 , the second connected the steel bands directly to the alternate retainers  22   a  illustrated in  FIG. 5 , and the third flatcar used links according to the present invention. It was found that two of the eighteen steel bands used with each of the first two flatcars broke, whereas none of the steel bands used with the third flatcar broke during the entire length of this run.  
         [0050]     It will be understood that the embodiments of the present invention which have been described are illustrative of some of the applications of the principles of the present invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention, including those combinations of features that are individually disclosed or claimed herein.