Abstract:
A tie system having at least one tie with a generally hollow, unitary body. The tie body is preferably made from a metal such as, but not limited to, steel. The tie is created as a unitary body and may be cast in its final form, however, in a preferred embodiment, the body is created as a tube which is then deformed into the final shape. Once the tube has the desired shape, a plurality of openings are cut therein. Components of the switch machine are then disposed within the tie body.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to a unitary body hollow tie for a railroad switch machine and, more specifically, to a unitary body hollow tie structured to substantially enclose a plurality of substantially straight elongated rods that extend between a switch machine actuator and a pair of movable rails. 
         [0003]    2. Background Information 
         [0004]    Railroad switching systems are generally understood by persons skilled in the art. A typical railroad includes a pair of spaced rails disposed upon, and coupled to, a plurality of generally solid ties. The space between a pair of ties is called a “crib.” The ties, which are typically wood or concrete, are disposed upon a bed of ballast. The ballast also fills the cribs between the ties. The ballast is typically a loose aggregate such as, but not limited to, gravel which must be compacted, or “tamped,” periodically to maintain support of the railroad ties. Equipment is available to perform the tamping. Such equipment is commonly identified as a “tamping machine.” The tamping machines are structured to engage and vibrate the ballast disposed between the ties. Because the spacing between ties is generally regular, the tamping machines may be constructed to automatically advance along a railroad track while stopping and tamping the ballast in each crib. The tamping machines, however, must be manually controlled or not used at the location of a railroad switch machine. 
         [0005]    A railroad switch machine includes an actuator, a pair of movable rails and a linkage having a plurality of elongated connecting rods extending between the actuator and the movable rails. The actuator is structured to move the connecting rods, and therefore the movable rails, between a first position and a second position. Traditionally, the connecting rods were mainly disposed in a crib; however, to provide support to the movable rails, the connecting rods were coupled to the movable rails at a location over a tie. To be both disposed in a crib and coupled to the movable rails over a tie, the connecting rods typically include a number of complex bends. Such complex-bent linkage components are expensive to manufacture. Additionally, the ballast in the cribs through which the linkage components extend must be tamped by hand during a tamping operation to avoid damaging the linkage components. Moreover, since the accumulation of ice and the like within the ballast can cause the ballast material to freeze, linkage components extending through the ballast can become difficult to move under freezing conditions. 
         [0006]    To reduce the cost and complexity of such linkage components, hollow ties structured to substantially enclose a plurality of substantially straight connecting rods have been used. See for example, U.S. patent application Ser. No. 10/614,755, which is incorporated by reference. The linkage included lugs having vertical extensions that extended through upwardly facing openings in the tie. Thus, the connecting rods were not disposed within a crib and could be manufactured without complex bends. The ties used with such straight connecting rods were two-piece ties, generally split along a central plane. Such split ties could be installed in difficult to access locations. Such split ties, however, included additional coupling devices and insulators, all of which are subject to wear and tear. Further, the split ties had other disadvantages such as a lack of covers over the upwardly facing openings, a lack of a switch device actuator support and tie plates that did not extend over the upwardly facing openings. In this configuration the tie plates did not reinforce the tie about the upwardly facing openings. 
         [0007]    There is, therefore, a need for a tie assembly having a generally hollow, unitary body. 
         [0008]    There is a further need for a tie assembly having covers substantially extending over any upwardly facing openings in a hollow tie body. 
       SUMMARY OF THE INVENTION 
       [0009]    These needs, and others, are met by at least one embodiment of the invention set forth below which provides a tie assembly having at least one tie with a generally hollow, unitary body. The tie body is preferably made from a metal such as, but not limited to, steel. The tie is created as a unitary body and may be cast in its final form, however, in a preferred embodiment, the body is created as a tube which is then deformed into the final shape. Once the tube has the desired shape, the tube is cut to the appropriate length and a plurality of openings are cut therein. Components of the switch machine are then disposed within the tie body. That is, components such as connecting rods are disposed within the tie body and structured to move within the tie body. Other components of the switch machine, such as lugs, are coupled to the rods and extend upwardly through the openings. The lugs are further coupled to the movable rails of the switch machine. 
         [0010]    Preferably, the tie is part of a larger tie system that includes a first tie assembly and a second tie assembly, as well as a pair of support ties structured to support a switch machine actuator. That is, as in the prior art, the switch machine preferably has two sets of rods, a first plurality of substantially straight, elongated rods, and a second plurality of substantially straight, elongated rods. Each set of rods is coupled to the movable rails via a first plurality of lugs and a second plurality of lugs, respectively. Accordingly, the tie system includes two unitary body tie assemblies, a first tie assembly and a second tie assembly, each having a hollow, unitary body tie. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which: 
           [0012]      FIG. 1  is an isometric view of a railroad and switch machine. 
           [0013]      FIG. 2  is a side view of a tie body. 
           [0014]      FIG. 3  is a top view of a tie body. 
           [0015]      FIG. 4  is a top cross-sectional view of a tie body. 
           [0016]      FIG. 5  is a partial view of a switch machine. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    As used herein, the word “unitary” means a component is created as a single piece or unit; that is, a component that includes pieces that are created separately and then coupled together, e.g., by fasteners, welding or any other method, is not a “unitary” component or body. 
         [0018]    As used herein, “coupled” means a link between two or more elements, whether direct or indirect, so long as a link occurs. 
         [0019]    As shown in  FIG. 1 , a railroad  10  includes a pair of spaced, fixed rails, a first fixed rail  12  and a second fixed rail  14 , disposed on a plurality of ties  16 . The ties  16  are, typically, supported by a bed of ballast  18  which is a loose aggregate such as, but not limited to, gravel. The railroad  10  further includes a switch machine  20  that is structured to allow a railroad vehicle to move between the rails  12 ,  14  and another set of rails (not shown). The switch machine  20  includes a pair of movable rails, a first movable rail  22  and a second movable rail  24 , an actuator  26 , a first plurality of substantially straight, elongated rods  28 , a second plurality of substantially straight, elongated rods  30 , a first plurality of lugs  32 , and a second plurality of lugs  34 . The movable rails  22 ,  24  have a more narrow gage than the fixed rails  12 ,  14 , and the movable rails  22 ,  24  are disposed within, and extend generally parallel to, the fixed rails  12 ,  14 . More specifically, the movable rails  22 ,  24  are structured to move between a first position, wherein the first movable rail  22  is immediately adjacent to the first fixed rail  12  and the second movable rail  24  is spaced from the second fixed rail  14 , and a second position wherein the first movable rail  22  is spaced from the first fixed rail  12  and the second movable rail  24  is immediately adjacent to the second fixed rail  14 . The movement of the movable rails  22 ,  24  is effected by the actuator  26 . That is, the actuator  26  is coupled to both the first and second pluralities of elongated rods  28 ,  30 . The first and second pluralities of elongated rods  28 ,  30  are coupled to the first and second pluralities of lugs  32 ,  34 . The first and second pluralities of lugs  32 ,  34  are coupled to the movable rails  22 ,  24 . The actuator  26  is structured to move the first and second pluralities of elongated rods  28 ,  30  longitudinally between a first and second position. The movement of the first and second pluralities of elongated rods  28 ,  30  is transferred to the first and second pluralities of lugs  32 ,  34  which in turn move the movable rails  22 ,  24  between the first and second position. 
         [0020]    The switch machine  20  further includes a tie system  40  structured to support the actuator  26  and partially enclose the first and second pluralities of elongated rods  28 ,  30 . The tie system  40  includes a first tie assembly  42 , a second tie assembly  44 , and may include a first support tie  46  and a second support tie  48 . Each tie assembly  42 ,  44  includes a generally hollow, unitary body  50 . As shown in  FIGS. 2-4 , the tie assembly tie body  50 , preferably, has a generally rectangular, hollow cross-section including a generally planar bottom plate  52 , having a first side  54  and a second side  56 , a first vertical, generally planar side plate  58 , a second vertical, generally planar side plate  60 , and a generally planar top plate  62 . The top plate  62  has an upper surface  64 . The tie body first side plate  58  extends from the first tie assembly body bottom plate first side  54 . The tie body second side plate  60  extends from the body bottom plate second side  56 . The tie body top plate  62  extends between the tie body first side plate  58  and the tie body second side plate  60 . Although each tie body  50  includes a plurality of generally flat plates  52 ,  58 ,  60 ,  62 , the tie body  50  is a unitary body created as a single component. That is, the tie body  50  is originally created as a tubular element. The tubular element may be cast or extruded in the appropriate size/shape, or the tubular element may be cast or extruded as, for example, a round tube. Such a round tube would be altered by a press or similar device to reshape the tubular element into the desired tie body  50  shape. The generally flat plates  52 ,  58 ,  60 ,  62  of the tie body  50  are not coupled together by a coupling device such as, but not limited to, fasteners or welding. The tie body  50 , preferably, has a length of between about 136 inches and 165 inches, and more preferably, about 160 inches. The tie body upper surface  64  has at least one opening  66  and preferably a first lug opening  67 , a second lug opening  68 , and a switch machine actuator opening  69 . The first and second lug openings  67 ,  68  are disposed on the medial portion of the tie body upper surface  64 . The switch machine actuator opening  69  is disposed adjacent to one end of the tie body  50 . 
         [0021]    As the tie body  50  for the first tie assembly  42  and the second tie assembly  44  are substantially similar, identical reference numbers will be used to refer to either the first tie assembly body  50 ′ or the second tie assembly body  50 ″. As indicated in the previous sentence, however, when there is a need to refer to a specific tie body  50 , for example the tie body  50  in the first tie assembly  42 , the reference numbers will hereinafter be identified with a single prime symbol, for example: the first tie assembly body  50 ′. This notation will also be shown in the Figures. Similarly, when referring to the tie body  50  in the second tie assembly  44 , the reference numbers will hereinafter be identified with a double prime symbol, for example: the second tie assembly body  50 ″. 
         [0022]    The tie body  50  also includes a heater mounting  70  disposed within the tie body  50 . The heater mounting  70  is structured to support an elongated heater element  72  extending generally parallel to the longitudinal axis of the tie body  50 . The heater element  72  is coupled to a power source and a control unit (not shown) and is structured to generate heat. The heater mounting  70 , preferably, includes a plurality of brackets  74  disposed on either the bottom plate  52 . 
         [0023]    As shown in  FIG. 5 , each tie assembly  42 ,  44  further includes a tie plate assembly  80 . As with the tie bodies  50 , the first tie assembly tie plate assembly  80 ′ and the second tie assembly tie plate assembly  80 ″ are substantially similar. As such, the following description shall address a tie plate assembly  80  that may be included with either the first tie assembly  42  or the second tie assembly  44 . It is understood that when the description and the Figures address a tie plate assembly  80  included with the first tie assembly  42 , the reference numbers will include a single prime symbol. Similarly, it is understood that when the description and the Figures address a tie plate assembly  80  included with the second tie assembly  44 , the reference numbers will include a double prime symbol. The tie plate assembly  80  includes at least one tie plate  82  and at least one insulator  84 . The at least one tie plate  82  includes a tie plate body  81  and an opening or slot  86 , discussed below, and a track channel  83 . As is known in the art, the track channel  83  is structured to have a fixed rail  14  disposed therein. The fixed rail  14  is coupled to the at least one tie plate  82  by a fastening device, such as, but not limited to a clip  85 . 
         [0024]    The at least one tie plate  82  is coupled to the tie body upper surface  64  and disposed over the tie body at least one opening  66 . The at least one insulator  84  is disposed between the at least one tie plate  82  and the tie body upper surface  64 . The at least one insulator  84  is structured to prevent current from passing between the at least one tie plate  82  and the tie body  50 . 
         [0025]    In one embodiment, each tie plate assembly  80  includes a first tie plate  90 , a second tie plate  92 , a first insulator  94  and a second insulator  96 . The first tie plate  90  has a generally flat body  100  defining a slot  102 . The second tie plate  92  also has a generally flat body  104  defining a slot  106 . The first tie plate  90  is coupled to tie body upper surface  64  over the first lug opening  67 . The first insulator  94  is disposed between the first tie plate  90  and tie body upper surface  64 . The second tie plate  92  is also coupled to the tie body upper surface  64  over said second lug opening  68 . The second insulator  96  is disposed between the second tie plate  92  and the tie body upper surface  64 . Preferably, each tie plate assembly  80  also includes a gage insulator  110  as well. The gage insulator  110  has a non-conductive body  112 . The gage insulator  110  is disposed between the first tie plate  90  and the second tie plate  92  and maintains the first tie plate  90  and the second tie plate  92  spacing. The width of the gage insulator  110  may vary as required to maintain the desired spacing of each tie plate track channel  83 , and therefore maintain the desired spacing of the fixed rails  14 . 
         [0026]    Each tie assembly  42 ,  44  preferably includes a cover assembly  120 . As before, while only one cover assembly  120  is discussed below, if needed for clarification in the specification and the figures, components of the cover assembly  120  associated first tie assembly may be identified with a single prime symbol and components of the cover assembly  120  associated second tie assembly may be identified with a double prime symbol. For example, there is a first tie assembly cover assembly  120 ′ and a second tie assembly cover assembly  120 ″. Each cover assembly  120  includes a machine actuator opening cover  122 , a first lug opening cover  124  and a second lug opening cover  126 . The machine actuator opening cover  122  is structured to cover the tie body machine actuator opening  69 . The first lug opening cover  124  is structured to cover the first lug opening  67 . The second lug opening cover  126  is structured to cover the first lug opening  68 . The covers  122 ,  124 ,  126  are structured to be spaced above the tie body upper surface  64  while extending substantially over the associated openings  69 ,  67 ,  68  respectively. In this configuration, ballast and other debris is substantially prevented from falling vertically into the tie body  50 . The first plurality of lugs  32  and the second plurality of lugs  34 , however, may move laterally in the space between the covers  122 ,  124 ,  126  and the tie body upper surface  64 . 
         [0027]    The first support tie  46  has a body  130  that is, preferably, structured to be disposed on the outer side of the fixed rails  14  immediately adjacent to the first tie assembly tie body  50 ′. The first support tie body  130  has a length, preferably, between 30 inches and 36 inches, and more preferably 33 inches. The first support tie body  130  has an upper surface  132  having a saddle block support  134 . The first tie assembly saddle block support  134  is structured to support the switch machine actuator  26 . The first tie assembly saddle block support  134  has a first block  136  and a second block  138 . The first tie assembly first block  136  and the first tie assembly second block  138  extend upwardly from the first tie assembly support tie upper surface  64 ′. 
         [0028]    The second support tie  48  has a body  140  that is, preferably, structured to be disposed on the outer side of the fixed rails  14  immediately adjacent to the second tie assembly tie body  50 ″. The second support tie body  140  has a length, preferably, between 30 inches and 36 inches, and more preferably 33 inches. The second support tie body  140  has an upper surface  142  having a saddle block support  144 . The second tie assembly saddle block support  144  is structured to support the switch machine actuator  26 . The second tie assembly saddle block support  144  has a first block  146  and a second block  148 . The second tie assembly first block  146  and the second tie assembly second block  148  extend upwardly from the second tie assembly support tie upper surface  64 ″. 
         [0029]    While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.