Patent Application
20190017227
The present invention relates generally to an apparatus and method for repairing shoulders of a railroad system that are attached to ties to hold rails in place and more specifically, to a shim and method of attaching the shim to a shoulder of a railroad system to compensate for material loss due to extended wear of the shoulder.
Railroad systems are commonly used in many parts of the world as a means of transportation (e.g., for freight and people). Railroad systems typically include rails that are supported on ties (e.g., commonly comprised of concrete) by a pad that is positioned between two shoulders (e.g., commonly comprised of iron). More specifically, a resilient pad is disposed between two shoulders on ties with plastic insulators coupled to the pads and abutting each of the shoulders. The pads are resilient to provide a smoother ride for the train and to compensate for slight size and position variations of the ties. As each of the wheels of a moving train passes over each of the ties, the weight of the train causes the rail to travel slightly downward on the pad, causing the sides of the plastic insulators to rub against a face of the shoulders. Over time, this repeated action causes noticeable wearing of the shoulder face. This erosion is increased when sand and other abrasive particles are lodged between the insulator and the shoulder face. The same action causes a wear on the sides of the insulators as well. This gap can be sufficiently large to allow the pad disposed between two adjacent shoulders and the rail associated with the worn shoulder to shift. In some instances, this lateral shift can be sufficiently large to cause the gauge to be too wide to meet the standard railroad specifications.
Plastic insulators are designed to last as long as rail sections and therefore it is relatively easy and simple to replace worn insulators (and pads, if necessary) at the same time as the rails. However, the shoulders are embedded into concrete ties and cannot be removed therefrom. Therefore, until now, the only way to correct for excessive wear of a shoulder face was to replace the entire concrete tie, which is a very expensive and time consuming process.
The present invention relates generally to a shim that is disposed between two components to address gaps or voids created over time between a shoulder and an insulator of a rail support. The shim, which can be made of steel plate or a similarly durable material, can be sized and shaped to cover the worn face of the shoulder. The shim can be attached to the shoulder, for example, by an adhesive, such as an epoxy.
In an embodiment, to fill a gap(s) or void(s) in a shoulder of a railroad system, the shim is inserted and attached to the respective shoulder. In another embodiment, a section of track is removed from the ties, with the original shoulders remaining imbedded in the ties. The existing rails and rail supports (e.g., plates, pads, clips, insulators, etc.) are replaced with new ones as needed and shims are attached to the shoulders as part of the replacement process. In another embodiment, the shims are incorporated or imbedded into the insulators prior to the replacement process.
The shoulder 18 includes a plurality of legs 18A that are configured to penetrate the tie 20. In this manner, a fastener 30, which includes an abrasion plate 32, a bottom pad 33, which could be a foam gasket or other material, a top pad 34 and two insulators 36, 38, is sandwiched between the rail flange 14 and the tie 20.
The top pad 34 can be made of a high impact plastic and include a generally H-shaped outline with a main body 40 and two transversal sides 42 and 44 (the terms transversal and longitudinal are used herein with reference to the longitudinal axis of rail 10).
The sides of pad 34 are formed with two respective rectangular cutouts 46 and 48 designed to wrap around the insulators 36, 38, respectively, as seen in
The pad 34 also has a first set of circular dimples 80 on its top surface and a second set of circular dimples (not shown) on its bottom surface. The two sets of dimples have the same size dimples but the dimples on the bottom surface are laterally offset so that they do not match the positions of top dimples 80. Both sets of dimples are distributed evenly across respective surfaces of the pad 34. It has been shown that patterns with this distribution are effective in converting the vertical forces on the rails 10 and fasteners 30 can be effectively diffused and spread across the surface of pad 34.
The abrasion plate 32, which can be made of a high impact plastic and is generally H-shaped with a flat portion 60 and two transversal sides with cutouts 62 and 64 similar to cutouts 42, 44 on the pad 34. The plate 32 further includes arms 70 disposed along the cutouts 62, 64. Tabs 66 are provided in the middle of each cutout 62, 64. Each arm 70 is formed with a raised wall 72 having an arcuate shape. These walls 72 are sized and shaped so that they are complementary to the curved sides 56.
Each arm 70 also holds a coupling stalk 74 rising vertically upwards, above, the flat portion 60 as seen in
The flat section 60 is formed with a pattern of protrusions 58 on its top surface 60. The protrusions 58 are evenly distributed at least on the portion of the plate 32 that is below rail 10. The protrusions 58 are constructed and arranged so that when the pad 34 is positioned on top of plate 32, each protrusion 58 fits and extends into a matching dimple on the bottom surface of the pad 34. Preferably, the diameter of the dimples is larger than protrusions 58. The diameter of a portion of the stalks 74 disposed below their heads 76 is also smaller than the diameters of holes 54. Thus, the elements of the plate 32 and pad 34 are dimensioned to allow the pad 34 and plate 32 to shift laterally with respect to each other.
The insulators 36 and 38 are also made of a high impact plastic material. Each has an elongated body 90 with a side wing 92, as shown in
Preferably, each insulator is provided at its longitudinal ends with respective round extensions 96. Each extension is formed with a hole 98, as shown in
The elements of the fastener 30 are assembled together by placing the pad 34 over the plate 32 and pushing it down to force the four stalks 74 through holes 54. The insulators 36, 38 include openings 98 that are then aligned with the stalks 74 and mounted to the stalks 74 such that the plate 32 is arranged between the pad 34 and the insulators 36, 38, thereby forming a fastener assembly that can be easily shipped to a desired destination and used to mount rail 10 on the ties 20.
It is important to note that the two shoulders 18 are embedded carefully into the concrete tie 20 with their faces 18B parallel to each other to engage the respective insulators 36, 38. In addition, the two fasteners 30 are placed at a predetermined distance from each other on each tie 20. This distance defines the spacing or gauge of the rails 10.
As discussed above, the insulators 36, 38 are made of an electrically insulating material and are provided to provide electrical isolation between the shoulders 18 and rails 10. The insulators are normally attached to the pad and each has a front face 36A that is in contact with the front face 18B of the respective shoulder 18, as shown somewhat diagrammatically in
A shoulder 18 typically has a body 18D that includes a front face 18B, a top surface 18C and two side walls 18E. As shown in
According to the present invention, a worn shoulder can be repaired using a shim 100 sized to fit over the face of the shoulder as shown in
The shim 100 is attachable to the shoulder 18 using an adhesive such as an industrial-strength epoxy 120. Preferably, the epoxy must be weatherproof since the track systems are frequently installed in locations that are subjected to inclement weather conditions with large temperature and humidity ranges. One such epoxy is available under the name of SRP 210 or Spikefast® Polyurethane available from Willamette Valley Company, Eugene, Oreg. Other adhesives may be used as well. In one embodiment of the invention, the shim 100 is simply attached to the shoulder, with the epoxy 120 and the shim 100 feeling the gap g. However, a better practice is to remove the fastener 30 before installing the shim 100 and replace it, or at least some of its components, as necessary.
A process 200 for repairing a rail section using a shim is shown in
Then, preferably new fasteners (including pads and insulators) are installed, if necessary, unless the old ones are good enough. As part of this step, a lubricant such as white lithium grease is applied between the insulators and the shoulder 18 to reduce friction, retard mold formation, etc. Next, a new rail segment is positioned on the rail supports and installed, and clips are installed to hold the rail segment in place. Finally, the ends of the rail segment are welded or otherwise attached to the adjacent rail segments.
The process described in conjunction with the flow chart of
In an alternate embodiment, a fastener 300 is provided that incorporates a shim. As shown in
As can be seen in
In this later embodiment, epoxy 230 (see
Although the description above and figures contains much specificity, the details provided should not be construed as limiting the scope of the embodiments, but merely as describing some of the features of the embodiments. The description and figures should not to be taken as restrictive and are understood as broad and general teachings in accordance with the present invention. While the embodiments have been described using specific terms, such description is for illustrative purposes only, and it is to be understood that modifications and variations to such embodiments, including, but not limited to, the substitutions of equivalent features and terminology may be readily apparent to those of skill in the art based upon this disclosure without departing from the spirit and scope of the invention. For example, in the embodiment described above, the rail is heated after the shim is applied. Alternatively, the rail may be heated by conventional means before the shim is applied. The embodiment described above uses a polyurethane as the adhesive, however other adhesives may be used as well to achieve the same purpose. The embodiment described above includes a shim made of sheet metal. Alternatively, a plastic material, such as a high strength plastic material may be used as well. Whether the shim is made of metal or plastic, it still has a predetermined or rigid shape. Alternatively, the adhesive itself may be used as the shim and it takes the desired shape as the rail and the insulator are assembled.
