Patent Publication Number: US-11396729-B2

Title: Direct fixation fastener having interlocking eccentrics for lateral adjustment

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to a fastener for track rail, and more particularly to a direct fixation fastener having lateral positioners with eccentrics interlocking with a frame. 
     BACKGROUND 
     Rail equipment is used across the world for transportation of persons and all manner of goods and equipment. Rail lines for freight or passenger service, are formed by parallel track rails supported upon a concrete or gravel substrate, for instance, and will be familiar to most. Depending upon the design of the rail line and the type of substrate, a variety of different mechanisms are used for positioning, supporting, and fastening the rails as well as managing loads and vibrations transmitted by way of the rail and fasteners between rail equipment and the underlying substrate. 
     Rail fastening and fixation systems range from simple plates that attach rails to wooden ties by way of spikes, to highly engineered direct fixation fasteners formed from an assembly of metallic and non-metallic components. One known direct fixation fastener for track rail is set forth in U.S. Pat. No. 10,081,915 to Constantine. The Constantine strategy has various applications, yet the field always welcomes improvements and/or alternative strategies. 
     Despite advanced construction techniques, a supporting substrate for a rail line, often poured concrete, can vary from specifications. Also, attachment mechanisms that are cast in place within the substrate, typically bolts or structures adapted to receive bolts, pedestal mounts, or others can vary from intended placement or positioning, or potentially even migrate or deform from specifications over time. 
     SUMMARY OF THE INVENTION 
     In one aspect, a track rail fastener includes a fastener body having a top plate, a frame, and an overmolded jacket supporting the top plate and the frame in spaced relation to one another. The frame has a first positioner bore and second positioner bore formed therein. The track rail fastener also includes a first lateral positioner and a second lateral positioner including a first eccentric and a second eccentric, respectively. The first eccentric and the second eccentric each define a center axis and have formed therein an axially extending bore offset in relation to the center axis. The frame further includes axially extending slots within each of the first positioner bore and the second positioner bore. The first eccentric and the second eccentric each include axially extending external teeth interlocked with the axially extending internal slots within the first positioner bore and the second positioner bore, respectively. 
     In another aspect, a direct fixation fastener includes a fastener body having a top plate with an upper rail surface extending in a fore-aft direction, a frame, an overmolded jacket encasing the top plate and the frame, and a positioner bore formed in the fastener body at a location that is lateral to the upper rail surface. The direct fixation fastener also includes a lateral positioner including an eccentric defining a center axis and having formed therein an axially extending bore offset in relation to the center axis and structured to receive an elongate clamping member for clamping the fastener body to a substrate. The direct fixation fastener also includes axially extending internal slots within the positioner bore. The eccentric further includes axially extending external teeth structured to interlock with the axially extending internal slots at a range of angular orientations of the eccentric, relative to the center axis, within the positioner bore. 
     In still another aspect, a lateral positioning mechanism for a fastener includes a frame having a positioner bore formed therein, and including axially extending internal slots within the positioner bore. The lateral positioning mechanism also includes an outer eccentric defining a first center axis, and having axially extending external teeth interlocked with the axially extending internal slots of the frame, a first axially extending bore that is eccentrically arranged relative to the first center axis, and axially extending internal slots within the axially extending bore. The lateral positioning mechanism still further includes an inner eccentric defining a second center axis, a second axially extending bore that is eccentrically arranged relative to the second center axis, and axially extending external teeth interlocked with the axially extending internal slots of the outer eccentric. The outer eccentric is positioned in the positioner bore, and further includes a first circumferential flange in contact with the frame, and the inner eccentric is positioned in the first axially extending bore, and further includes a second circumferential flange in contact with the outer eccentric. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagrammatic view of a direct fixation track rail fastener, partially disassembled and supporting a track rail, according to one embodiment; 
         FIG. 2  is an elevational view of the fastener of  FIG. 1 ; 
         FIG. 3  is a diagrammatic view of internal parts of the fastener of  FIGS. 1 and 2 ; 
         FIG. 4  is a sectioned side diagrammatic view of portions of the fastener of  FIGS. 1 and 2 ; 
         FIG. 5  is a diagrammatic view of a direct fixation track rail fastener, partially disassembled, according to another embodiment; 
         FIG. 6  is a diagrammatic end view of the fastener of  FIG. 5  supporting a track rail; 
         FIG. 7  is a sectioned side diagrammatic view through a portion of the fastener of  FIGS. 5 and 6 ; and 
         FIG. 8  is an elevational view of the fastener of  FIGS. 5-7 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , there is shown a direct fixation track rail fastener  10  supporting a section of track rail  8 , according to one embodiment. Fastener  10  includes a fastener body  12  that supports track rail  8  upon a shim  6  that can be positioned upon a substrate, such as a poured concrete substrate. In other instances, a shim might not be used. Fastener  10  can be structured to support and clamp track rail  8  by way of a first rail clip or E-clip  56  and a second rail clip or E-clip  58  in a generally conventional manner. Elongate clamping elements in the nature of bolts  80  can be passed through fastener body  12 , through bores  4  in shim  6 , and coupled with receiving elements (not shown) within the underlying substrate, such as cast in place bolting elements. In other embodiments cast-in-place elements could extend up through fastener body  12  and be coupled with nuts or the like. Referring also to  FIGS. 2 and 3 , fastener body  12  includes a top plate  14 , a frame  16 , and an overmolded jacket  18  supporting top plate  14  and frame  16  in spaced relation to one another. Fastener body  12 , and in particular frame  16 , has a first positioner bore  20  and a second positioner bore  22  formed therein. As shown in  FIG. 3 , top plate  14  also includes an upper rail surface  46  extending in a fore-aft direction. A fore or forward direction is shown generally by way of arrow  47  in  FIG. 3 , and a rearward or aft direction is shown by way of arrow  49 . Each of top plate  14  and frame  16  can include a one-piece metal body, such as a casting, and may be supported in the spaced relation by way of overmolded jacket  18  such that top plate  14  and frame  16  are not physically in contact with one another. Instead, material of overmolded jacket  18  extends between top plate  14  and frame  16  for purposes of positioning the components, attenuating vibrations, cushioning, resiliently accommodating shear loads and twisting loads, for instance, and providing electrical insulation. Overmolded jacket  18  could be formed from a non-metallic material such as an elastomeric material, natural or synthetic rubber, or a variety of other non-metallic materials. Top plate  14  has a lower surface  60 , and frame  16  has an upper surface  62 . A clearance  66  may extend between lower surface  60  and upper surface  62 . When constructed for service, the material of overmolded jacket  18  can fill clearance  66 . Top plate  14  may also include a first shoulder  48  extending in a first outboard direction from upper rail surface  46 , a leftward lateral direction on  FIG. 3 , and a second shoulder  50  extending in a second outboard direction, a right lateral direction in  FIG. 3 , from upper rail surface  46 . Upper rail surface  46  can be free of, or substantially free of, material of overmolded jacket  18 . A first rail clip bore  52  and a second rail clip bore  54  receive first E-clip  56  and second E-clip  58 , respectively, and are formed between frame  16  and first shoulder  48  and second shoulder  50 , respectively. A first end wall  68  of frame  16  extends generally upwardly at a location that is outboard of first shoulder  48 . A second end wall  70  of frame  16  extends generally upwardly at a location that is outboard of second shoulder  50 . Fastener body  12 , and in particular frame  16 , further has a first positioner bore  20  and a second positioner bore  22  formed therein, each located laterally of upper rail surface  46 . First positioner bore  20  extends vertically through fastener  12  and frame  16  at a location that is forward of first shoulder  48 , and second positioner bore  22  extends vertically through fastener body  12  and frame  16  at a location that is aft of second shoulder  50 . It can thus be noted that first positioner bore  20  and second positioner bore  22  can be understood to be offset in the fore-aft direction from first shoulder  48  and second shoulder  50 , respectively, placing first positioner bore  20  and second positioner bore  22  approximately in a forward left and a right back quadrant, respectively, of fastener body  12 . In other embodiments, first positioner bore  20  and second positioner bore  22  could be arranged closer to a fore-aft medial location of fastener body  12 . Still other embodiments could include a greater number of positioner bores than two, however, a total of two positioner bores provides a practical implementation strategy. 
     Fastener  10  further includes a first lateral positioning mechanism or positioner  24  and a second lateral positioning mechanism or positioner  26  structured for positioning within first positioner bore  20  and second positioner bore  22 , respectively. First lateral positioner  24  includes a first eccentric  28  defining a first center axis  32 . Second lateral positioner  26  includes a second eccentric  30  defining a second center axis  33 . Axes  28  and  30  can be geometric center axes of eccentrics  28  and  30 . First eccentric  28  and second eccentric  30  have formed therein, respectively, a first axially extending bore  34  and a second axially extending bore  36 , offset in relation to the corresponding center axis  32  and  33 . In some instances, center axes  32  and  33  could pass through axially extending bores  34  and  36 , respectively, and axially extending bores  34  and  36  still understood as offset in relation to the corresponding center axis, so long as the axially extending bores are not centered upon the corresponding center axis. In the illustrated embodiment, center axes  32  and  33  do not extend through the axially extending bores. 
     With continued reference to  FIG. 2 , there can be seen in an elevational view, that in first eccentric  28  another axis  39  is generally at a center of axially extending bore  34 . Axis  39  represents a location of a center axis that might be observed for a bolt, a nut, or another attachment element that is cast-in-place in an underlying substrate but is offset from an axis location  37  that is specified. In other words, axis  39  might represent an actual axis location offset by an offset distance  84  from a desired or intended axis location  37 . Eccentric  28  may be structured for positioning at any of a range of angular orientations about its own center axis  32  to enable axially extending bore  34  to be positioned for accommodating bolts or other structures for attaching fastener  10  to the underlying substrate that are out of specification. During installation or adjustment, eccentric  28  can be rotated about center axis  32  to position axially extending bore  34  appropriately for clamping fastener  10  to the substrate, accommodating errors or tolerances in the structure of the underlying substrate itself, or in locations of cast-in-place components. Adjustments of fastener  10  can also be undertaken in response to factors such as wear of rail  8 , to maintain a proper rail gauge over time. This description of the functionality of eccentric  28  also applies to eccentric  30 , and generally to other eccentrics in direct fixation track rail fasteners according to the present disclosure. 
     It can further be noted that frame  16  includes axially extending internal slots  38  within first positioner bore  20 , and axially extending internal slots  40  within second positioner bore  22 . Axially extending internal slots  38  and  40  may be formed integrally in frame  16 , and in the one-piece metal body formed thereby. Axially extending means in a direction parallel to an axis, in this case parallel axes  32  and  33  as the case may be. First eccentric  28  and second eccentric  30  each include axially extending external teeth  32  and  34 , respectively, structured to interlock with axially extending internal slots  38  and  40  within first positioner bore  20  and second positioner bore  22 , respectively. As used herein the term “teeth” contemplates serrations, flutes, roundings, or other structures that can mate with slots  38  and  40 , which are complementarily shaped to teeth  32  and  34 . Certain earlier direct fixation fasteners employed eccentrics that were clamped to and/or compressed against an underlying substrate or shim to fix their relative angular orientation about their center axes by way of frictional forces. According to the present disclosure, interlocking of axially extending slots  38  and  40  with axially extending external teeth  42  and  44  enables locking of first eccentric  28  and second eccentric  30  at desired angular orientations without the need for clamping or otherwise directly contacting the eccentrics with the underlying substrate, shim, et cetera. It can further be noted from  FIG. 3  and  FIG. 4  that frame  16  includes a first clamping surface  72  extending circumferentially around first positioner bore  20 , and a second clamping surface  74  extending circumferentially around second positioner bore  22 . Clamping surfaces  72  and  74  may be free of, or substantially free of, material of overmolded jacket  18 . 
     First eccentric  28  also includes a circumferential flange  76  and second eccentric  30  also includes a circumferential flange  78 , in contact with the corresponding one of first clamping surface  72  and second clamping surface  74 .  FIGS. 3 and 4  show an upwardly projecting wall  82  having clamping surface  74  formed thereon. A similar geometry and construction associated with first positioner bore  20  can be seen as well in  FIG. 3 . The upwardly projecting wall  82  extends circumferentially around second positioner bore  22 , and can enable second eccentric  30  to be seated directly upon frame  16 , with second eccentric  30  suspended above the substrate. Second eccentric  30  can be formed of a metal material, such that the contact between second eccentric  30  and frame  16  is metal-to-metal contact. First eccentric  28  may be analogously structured to seat It will be recalled that frame  16  and top plate  14  may not be in direct contact with one another, hence, track rail  8 , top plate  14 , and other components are not in electrical contact with frame  16 , nor the underlying substrate. Similar configurations and properties are associated with other embodiments, further discussed below. 
     Referring now to  FIG. 5 , there is shown a track rail fastener  110  according to another embodiment, and including a fastener body  112  having a top plate  114 , a frame  116 , and an overmolded jacket  118  supporting top plate  114  and frame  116  in spaced relation to one another. Fastener body  112 , and frame  116  in particular, has a first positioner bore  120  and a second positioner bore  122  formed therein. A first lateral positioner  124  and a second lateral positioner  126  include a first eccentric  128  and a second eccentric  130 , respectively. First eccentric  128  and second eccentric  130  have formed therein an axially extending bore  134  and  136 , respectively, in a manner generally analogous to that described in connection with the foregoing embodiment. Frame  116  further includes axially extending internal slots  138  and  140  within each of first positioner bore  120  and second positioner bore  122 , respectively. In  FIG. 5 , first lateral positioner  124  is shown disassembled, and second lateral positioner  126  is shown assembled. It should be understood that first lateral positioner  124  and second lateral positioner  126  may be substantially identical, and therefore the description of first lateral positioner  124  herein should be understood to refer generally to second lateral positioner  126 . 
     In the foregoing embodiment of track rail fastener  10 , each of first eccentric  28  and second eccentric  30  is one-piece. Track rail fastener  110  differs from track rail fastener  10  in that first eccentric  128  includes an outer eccentric  129  and an inner eccentric  131 . Second eccentric  130  is analogously configured. Inner eccentric  131  is positioned within axially extending bore  134  in the corresponding outer eccentric  129 . Track rail fastener  110  also differs from fastener  10  in that rather than a bolt that is passed vertically downward through the fastener, in track rail fastener  110  bolts or the like  180  may be cast-in-place in the underlying substrate, or in a preformed plinth, for example, and extend vertically upward through a shim  106 , to be coupled with nuts  135  that are tightened down to clamp first lateral positioner  124  and second lateral positioner  126 , along with fastener body  112 , to the underlying substrate, or to shim  106  where used. 
     It will be recalled that frame  116  further includes axially extending internal slots  138 , formed substantially similar to axially extending internal slots  38  in frame  16  of fastener  10 . Outer eccentric  129  further includes axially extending external teeth  142  interlocked with the axially extending internal slots  138  within first positioner bore  120 . Inner eccentric  131  can include a plurality of axially extending external teeth  139  that are interlocked with axially extending internal slots  141  formed within axially extending bore  134  in outer eccentric  129 . 
     Referring also to  FIGS. 6 and 7 , there can be seen additional details of the structure and manner by which fastener  110  is clamped to shim  106  and/or the underlying substrate. A nut  135  can be threaded onto elongate clamping element or bolt  180 , with a washer or the like  143  clamped between nut  135  and inner eccentric  131 . Inner eccentric  131  includes a circumferential flange  178  that is in contact with and clamped upon outer eccentric  129 . Outer eccentric  129  also includes a circumferential flange  134  that is in contact with and clamped upon frame  116 . It will be recalled from the foregoing discussion of fastener  10  that an eccentric in the present disclosure may not be clamped into contact with the underlying substrate or a shim, but instead is clamped directly to the frame of the fastener. As can be seen in  FIG. 7 , a clearance  179  extends between each of outer eccentric  129  and inner eccentric  131  and shim  106 . The bottom surface of frame  116  may be planar and understood to define a mounting plane, and each of first eccentric  128  and second eccentric  130 , including each of outer eccentric  129  and inner eccentric  131  as shown in  FIG. 7 , is recessed from the planar lower surface of frame  116  such that clearance  179  extends vertically between the mounting plane and each of outer eccentric  129  and inner eccentric  130 . It can thus be understood that a clamping load is transmitted from nut  135  to washer  143 , to inner eccentric  131 , and by way of circumferential flange  178 , to outer eccentric  129 , and by way of circumferential flange  176  to frame  116 . The clamping load clamps frame  116  directly to shim  106 , or to the underlying substrate directly if frame  116  is rested directly thereon. Outer eccentric  129  contacts frame  116  at a metal-to-metal interface  181 . Fastener  110  may be constructed generally analogously to fastener  10 , such that top plate  114  is electrically insulated by way of material of overmolded jacket  118  from frame  116 .  FIG. 8  illustrates an elevational view of fastener  110 , where it can be seen that a center axis  132  defined by outer eccentric  129  is offset from a center axis  133  defined by inner eccentric  131 . An upper rail surface  146  is also visible in  FIG. 8 . 
     INDUSTRIAL APPLICABILITY 
     Referring to the drawings generally, as explained above variability in construction practices, changes in response to environmental or wear conditions over time, or other factors can justify varying a lateral position of a track rail fastener. In the case of the embodiment of  FIGS. 1-4 , a technician can loosen elongate clamping members  80 , lift one or both of eccentrics  28  and  30  out of positioner bores  20  and  22 , and rotate one or both of eccentrics  28  and  30 , to reposition axially extending bores  34  and  36 , and then reinstall eccentrics  28  and  30 . Some adjustments could be achieved by repositioning only one of eccentrics  28  and  30 . If fastener  10  is to be shifted laterally in one direction or the other, it will typically be necessary to reposition each of eccentrics  28  and  30 . It has been observed that in some instances there can be some minor forward or aft repositioning of the fastener where both eccentrics are rotated, as the relative fore-aft position of axially extending bores  34  and  36  will change as bores  34  and  36  are rotated about center axes  32  and  33 . In the case of the embodiments of  FIGS. 5-8 , the use of dual eccentrics can allow the relative fore-aft locations of the axially extending bores  137  to be maintained. In other words, by rotating each of inner eccentric  131  and outer eccentric  129 , in each of lateral positioners  124  and  126 , in different directions, the interface with elongate clamping members  180  can be maintained at a constant fore-aft location, and it is therefore not necessary to shift fastener  110  forward or rearward at all. 
     The present description is for illustrative purposes only, and should not be construed to narrow the breadth of the present disclosure in any way. Thus, those skilled in the art will appreciate that various modifications might be made to the presently disclosed embodiments without departing from the full and fair scope and spirit of the present disclosure. Other aspects, features and advantages will be apparent upon an examination of the attached drawings and appended claims. As used herein, the articles “a” and “an” are intended to include one or more items, and may be used interchangeably with “one or more.” Where only one item is intended, the term “one” or similar language is used. Also, as used herein, the terms “has,” “have,” “having” or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.