Patent Publication Number: US-8985526-B2

Title: Swivel point connector for railroad switches

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to railway monitoring apparatus and, more particularly to a coupling mechanism for coupling railway apparatus to a railway. The present invention also relates to detection and railway switching systems employing such coupling mechanism. 
     2. Description of the Prior Art 
     Numerous different types of railroad switching equipment are known and understood in the railroad arts. It is generally understood that a railroad switch apparatus is employed to switch a train from a first set of railroad tracks onto a second set of railroad tracks. Such a railroad switch apparatus typically includes a pair of movable rails, a switch machine for moving the rails, a detection device for detecting the position of the rails, and assorted connective hardware that extends between the movable rails, the switch machine, and the detection device for various purposes. The switch machine provides the forces necessary to move the movable rails between a first position and a second position and to lock the movable rails in the first and second positions. The detection device monitors the position of the movable rails. 
     It is also known that railroad equipment including railroad switch apparatuses are typically subjected to extreme punishment and distortions due to the substantial forces and vibrations transmitted from passing railroad trains, as well as severe environmental conditions including heat, snow, and ice which can greatly distort and wear components. Railroad equipment thus is preferably designed and configured generally to resist the effects of such harsh conditions, and to perform reliably under such conditions. 
     It is further known that railroad tracks and other related equipment extend across many remote regions, commonly referred to as “dark territory”, and that trains commonly travel on such remote tracks at all hours of the day and night. As such, railroad personnel must be available to inspect and, if necessary, repair railroad equipment at numerous remote locations at any hour. As the skill level of railroad maintenance personnel varies greatly, railroad equipment is preferably of a relatively simple configuration that can be repaired with a minimal number of tools in order to limit the number of potential points of failure of such railroad equipment and to facilitate repair by virtually any railroad personnel no matter the skill level or the quantity of tools available to such personnel. 
     In order to ensure the proper functioning of railroad switch apparatuses in all types of weather conditions and to resist breakage and maladjustment of such switch apparatuses, the connective hardware that extends between a switch machine and a pair of movable rails has typically included connecting rods that have been substantially rigidly connected with function rods that are part of the switch machine and that are movable with respect to other parts of the switch machine. While such rigid connections generally enhance the reliability of railroad switch apparatuses, such rigid connections nevertheless increase the difficulty and expense of installing and maintaining railroad equipment due to the degree of alignment that must be attained between the switch machine and the movable tracks. 
     During installation and replacement of conventional railroad switch apparatuses, special care is required to align the switch machine with the movable tracks in order to ensure that the connective hardware that is rigidly connected between the switch machine and the movable tracks is properly connected, and that such connective hardware operates properly without the components thereof or the movable tracks binding during operation. Commonly, such conventional switch machines are mounted a distance from the rails of the railroad, typically on the wooden ties to which the rails were mounted or on cement pads near the wooden ties, with the base of the switch machine needing to be aligned either flush with the lower surfaces of the tracks or at a given vertical distance from such lower surfaces. Such alignment typically is burdensome and costly to achieve during initial construction, and is particularly difficult and time consuming after repair or replacement of a switch machine due to the gradual deterioration of railroad ties and the difficulty of reliably employing such ties to align a switch machine with railroad tracks. 
     Accordingly, there is room for improvement in structures that facilitate installation of a switch machine and connection thereof with the movable tracks of a railroad switch apparatus while providing the necessary reliability and resistance to the effects of environmental conditions in which the switch apparatus is employed. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention improve upon known designs by providing a mechanism for coupling a switch point to a point detector box, a detection system for detecting the position of a movable switch point of a railway, and a railway switching system. 
     In one example embodiment, a mechanism for coupling a switch point to a point detector box having a point detector bar is provided. The coupling mechanism comprises a first portion structured to be slidably coupled to the point detector bar and a second portion structured to be slidably coupled to the switch point. 
     The first portion may be structured to slide along a first axis and the second portion may be structured to slide along a second axis, the second axis being oriented generally perpendicular to the first axis. 
     The point detector bar may move relative to the point detector box generally along a third axis, the third axis being oriented generally perpendicular to the first axis. 
     The first and second portions may be portions of a generally cylindrical body disposed about a central longitudinal axis and the longitudinal axis may coincide with the first axis. 
     The first portion may comprise a generally smooth cylindrical shaft portion structured to slidably engage a generally spherical ball member disposed within a socket coupled to the point detector bar. 
     The second portion may comprise an engagement portion of a first diameter bounded by an adjacent portion having a greater diameter and wherein the second portion is structured to slidably engage an elongated aperture disposed on, in or coupled to the switch point. 
     The first portion may be disposed at or about a first end of a generally cylindrical body and the second portion may be disposed at or about a second end of the generally cylindrical body. 
     In another example embodiment, a detection system for detecting the position of a movable switch point of a railway is provided. The detection system comprises a point detector box having a point detector bar and a mechanism structured to couple the point detector bar to the movable switch point. The mechanism comprises a first portion slidably coupled to the point detector bar and a second portion structured to be slidably coupled to the movable switch point. 
     The first portion of the mechanism may be structured to slide along a first axis and the second portion of the mechanism may be structured to slide along a second axis, the second axis being oriented generally perpendicular to the first axis. 
     The point detector bar may move relative to the point detector box generally along a third axis and the third axis may be oriented generally perpendicular to the first axis. 
     The first and second portions of the mechanism may be portions of a generally cylindrical body disposed about a central longitudinal axis and the central longitudinal axis may coincide with the first axis. 
     The point detector bar may comprise a socket having a generally spherical ball member disposed therein and the first portion of the mechanism may comprise a generally smooth cylindrical shaft portion slidably coupled to the ball member. 
     The second portion of the mechanism may comprise an engagement portion of a first diameter bounded by an adjacent portion having a second diameter greater than the first diameter. The second portion of the mechanism may be structured to slidably engage an elongated aperture disposed on, in, or coupled to the switch point. 
     The first portion of the mechanism may be disposed at or about a first end of a generally cylindrical body and the second portion of the mechanism may be disposed at or about a second end of the generally cylindrical body. 
     In a further example embodiment, a railway switching system is provided. The railway switching system comprises a movable switch point and a detection system. The detection system comprises a point detector box having a point detector bar and a mechanism coupling the point detector bar of the point detector box to the movable switch point. The mechanism comprises a first portion slidably coupled to the point detector bar and a second portion slidably coupled to the movable switch point. 
     The first portion of the mechanism may be structured to slide along a first axis and the second portion of the mechanism may be structured to slide along a second axis, the second axis being oriented generally perpendicular to the first axis. 
     The point detector bar may move relative to the point detector box generally along a third axis and the third axis may be oriented generally perpendicular to the first axis. 
     The first and second portions of the mechanism may be portions of a generally cylindrical body disposed about a central longitudinal axis and the central longitudinal axis may coincide with the first axis. 
     The point detector bar may comprise a socket having a generally spherical ball member disposed therein and the first portion of the mechanism may comprise a generally smooth cylindrical shaft portion slidably coupled to ball member. 
     The second portion of the mechanism may comprise an engagement portion having a first diameter bounded by an adjacent portion having a second diameter greater than the first diameter and the second portion of the mechanism may slidably engage an elongated aperture disposed on, in, or coupled to the switch point. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full understanding of the disclosed concept can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which: 
         FIG. 1  is a plan view of a portion of a railroad including a railroad switch detection system in accordance with a non-limiting embodiment of the present invention; 
         FIG. 2  is an isometric view of a portion of the railroad switch detection system of  FIG. 1  showing a coupling mechanism and associated members; and 
         FIG. 3  is an exploded view of a portion of the view of  FIG. 2  showing details of a coupling mechanism in accordance with an embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As employed herein, the statement that two or more parts are “connected” or “coupled” together shall mean that the parts are joined together either directly or joined through one or more intermediate parts. Further, as employed herein, the statement that two or more parts are “attached” shall mean that the parts are joined together directly. Identical parts are provided with the same reference number in all figures. 
     As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality). 
     A railroad switch detection system  4  in accordance with the present invention is indicated generally in the plan view of  FIG. 1 . As will be set forth more fully below, the railroad switch detection system  4  advantageously includes a coupling mechanism  8  in accordance with the present invention. As will be better appreciated from the description herein, the inclusion of the coupling mechanism  8  into the railroad switch detection system  4  facilitates the initial assembly and installation as well as the operation, maintenance and repair of the railroad switch detection system  4 . 
     As shown in  FIG. 1 , the railroad switch detection system  4  is employed in conjunction with a portion of a railroad track that is depicted as including a plurality of ties  16  and a pair stock rails  18  and  20  that are fixedly mounted on the ties  16 . It is understood that an additional pair of stationary stock rails (not shown) extend generally away from the railroad switch detection system  4  in addition to the stock rails  18  and  20 . 
     The railroad switch detection system  4  includes a pair of movable rails  22  and  24  which are movable between a first position ( FIG. 1 ) in which the movable rail  22  is engaged with the stock rail  18  and a second position (not shown) in which the movable rail  24  is engaged with the stock rail  20 . Such alternate engagement of the movable rails  22  and  24  with the stock rails  18  and  20 , respectively, according to operation of a switching apparatus  26  coupled with the movable rails  22  and  24  permits a train to be switched from one set of tracks onto a second set of tracks according to known principles. Due to their switching function, movable rails  22  and  24  may commonly be referred as switch points. Switching apparatus  26  may comprise a manually operated or automated switching mechanism as known in the art without varying from the scope of the present invention. Movable rails  22  and  24  are also operatively connected with a point detector bar  28  of a point detector box  30  via coupling mechanism  8 , as discussed in further detail below. 
     Point detector box  30  may comprise one or more sensor devices suitable for detecting the movement and or relative positioning of point detector bar  28 , which is movably coupled to point detector box  30 . As shown in  FIG. 1 , point detector box  30  may be mounted directly to stock rail  18  or may be mounted a distance from rail  18 , such as, for example, on or near one or more of the plurality of ties  16 . In the embodiment shown in  FIG. 1 , point detector bar  28  is generally movable (slidably coupled) along an axis  32 . It is to be appreciated that other arrangements of point detector bars and detector boxes may be employed without varying from the scope of the present invention. Point detector bar  28  preferably includes an adjustable eye-bolt or ball and socket joint  34  (discussed in detail below) disposed on an end thereof. 
     Having thus described the overall arrangement of railroad switch detection system  4  a detailed description of coupling mechanism  8  will now be provided in conjunction with  FIGS. 2 and 3 . Referring to the exploded view of  FIG. 3 , coupling mechanism  8  includes a generally cylindrical body  10  disposed about a central longitudinal axis  12  and includes a first portion  38  and an opposite second portion  40 . First portion  38  is structured to be slidably coupled to point detector bar  28 . Preferably such slidable coupling is accomplished by first portion  38  being formed as a generally smooth cylindrical shaft portion that slidably engages the point detector bar  28  via ball and socket joint  34  ( FIG. 2 ) or other suitable structure. Referring to  FIG. 2 , ball and socket joint  34 , as the name implies, includes an outer, socket portion  34   a  that is adjustably coupled (preferably via a threaded member) to an end of point detector bar  28  and includes a generally spherical, smooth inner surface (not numbered). Ball and socket joint  34  further includes a generally spherical ball member  34   b , disposed within the inner surface of socket portion  34   a  in a manner such that ball member  34   b  may rotate freely in all directions without noticeable restriction from socket member  34   a . Ball member  34   b  includes an aperture (not numbered) through which first portion  38  of coupling mechanism  8  slidably engages and extends generally therethrough. As shown in  FIG. 2 , such slidable coupling allows for the first portion  38  of coupling mechanism  8  to slide relative to the point detector bar  28  generally along an axis  42 , which generally coincides with the central longitudinal axis  12  of the generally cylindrical body  10  and is oriented generally perpendicular to axis  32 , the axis along which the point detector bar  28  slides relative to point detector box  30 . It is to be appreciated that the independent rotation of ball member  34   b  within socket portion  34   a  allows for axis  42  and  32  to also be oriented other than perpendicular without binding, which is beneficial as such non-perpendicular alignments can commonly occur at various points during operation of movable rails  22  and  24 . It is also to be appreciated that the slidable coupling of the first portion  38  or coupling mechanism  8  with respect to the point detector bar  28  accommodates for axial movement (i.e., change of length) of movable rail  22  resulting from movement of the movable rail  22  during switching operations and/or due to fluctuations in temperature (which may cause movable rail  22  to expand or contract). 
     Second portion  40  of coupling mechanism  8  is structured to be slidably coupled to movable rail  22  such that second portion  40 , and thus the entirety of coupling mechanism  8 , is generally free to slide relative to movable rail  22  along axis  44 , which is oriented generally perpendicular to axis  42 , and thus conversely, movable rail  22  may freely move vertically with respect to coupling mechanism  8  (such as may commonly occur, for example, during passage of a train). In the example embodiment shown in  FIGS. 1-3 , such slidable coupling between the second portion  40  and movable rail  22  is accomplished via the interaction of second portion  40  with an elongated aperture  46  provided in a bracket  48  coupled to movable rail  22 . It is to be appreciated that such an elongated aperture  46  could also be provided in or on the movable rail  22  without varying from the scope of the present invention. In a preferred embodiment of the invention, such as shown in  FIG. 3 , the second portion  40  comprises an engagement portion  50  of generally square or rectangular shape that is sized to slide within elongated aperture  46 . Engagement portion  50  includes a threaded aperture  52  that is adapted to receive a bolt  54  disposed therein to loosely couple engagement portion  50  to bracket  48 . As further shown in  FIG. 3 , a plate member  56  or other suitable member is preferably provided adjacent bolt  54  to assist in the slidable engagement between coupling mechanism  8  and bracket  48 . As also shown in  FIG. 3 , an enlarged diameter portion  58  is provided adjacent second portion  50 . 
     While specific embodiments of the disclosed concept 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 the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.