Patent Publication Number: US-10766511-B2

Title: Cable driven railroad switch indicator

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a cable operated railroad switch indicator with a plurality of visual indicators which are selectively visible for signaling the position of a pair of railroad switchpoints independently of the mechanism for operating the switch so as to indicate safety conditions on a railroad track. 
     Brief Description of the Prior Art 
     The present switch indicator is a variation on the switch indicator described and claimed in U.S. Pat. No. 8,695,928 for Railroad Switch Indicator with Distance Amplifier, which is incorporated by reference herein. 
     In order to optionally switch a railroad train operating on one track to a second track, it is typical to provide a switch with a pair of switchpoints which are selectively movable horizontally to deflect the train toward one or the other of the tracks. The switchpoints may be driven by a manual, hydraulic or electrical powered mechanism. A signal is usually associated with the mechanism for operating the switch to visually indicate how the switch is lined. If a train runs through the switch or if the switchpoints are moved by vibrations of a train rolling over the track, the switchpoints may be moved into a mid position which is not reflected by the signal associated with the mechanism for operating the switch. 
     When a train runs through a switch, a flange on the wheels picks open the switchpoints. Depending on how sharp the wheels are, the distance that the switchpoints move may be much less than an inch and yet a misalignment of as little as 0.25 inch may result in a disastrous derailment. Manual mechanisms commonly miss such a small movement and even sophisticated electrically powered switch mechanisms with sensors for open and closed switchpoints may give a false signal. 
     BRIEF SUMMARY OF THE INVENTION 
     In view of the above, it would be desirable to have a railroad switch indicator that operates independently of the mechanism for operating the switch, for signaling the position of the switchpoints and that is mechanically linked via a flexible mechanical cable to a railroad switch distance amplifier mechanism. The flexible cable allows the railroad switch indicator to be positioned remotely from the railroad switch distance amplifier mechanism so that the railroad switch indicator can be placed in a highly visible and easily serviceable location such as off to the side and/or in an elevated position relative to the railroad track. 
     Another object of the invention is to provide a railroad switch indicator that signals movements of the switchpoints that may be missed by the mechanism for operating the switch and that defaults to a safe position signaling caution. It is also an object to provide a railroad switch indicator that does not depend on electricity and can be used with mechanically operated switches as well as electrically powered switches. Other objects and features of the invention will be in part apparent and in part pointed out hereinafter. 
     In accordance with the invention, a railroad switch indicator for use with a switch for switching a railroad train is provided. The switch includes a pair of outer stockrails and a pair of inner switchrails with the inner switchrails having first ends secured to a track bed and second ends terminating with switchpoints. The inner stocktails are connected by a traverse bar for conjoint lateral movement of the switchpoints between switching and therefore diverging and nonswitching and therefore non-diverging positions. 
     The multicolored reflective railroad signal illustrated in the drawings visually signals the position of a pair of railroad switchpoints independently of the mechanism for operating the switch. In this preferred embodiment, the signal is octagonal in shape so as to provide a plurality of reflectors that are easily visible from virtually any horizontal angle and therefore 360 degrees around the signal. Although it should be noted that the signal could be other shapes such as a circle, square, etc., have reflectors viewable also from the top or bottom or not have reflective surfaces viewable from 360 degrees around the switch indicator without deviating from the intent of the invention. 
     In the preferred embodiment the signal has a plurality of upper green reflectors located along the top perimeter of the signal and also a plurality of red reflectors located along the bottom perimeter of the signal. Although the signal could use reflectors having colors other than red and green without deviating from the intent of the invention. The signal could also incorporate powered LED&#39;s so as to improve the visibility of the signal. The signal could also have a translucent cover or no cover at all to let in ambient light to enhance the light output of translucent reflectors and therefore help to increase their visibility without deviating from the intent of the invention. 
     In the preferred embodiment the signal also has a vertically movable reflector blocking shield that is also octagonal in shape which can be moved up and down to selectively cover or uncover all or a portion of the upper green or lower red reflectors. This reflector blocking shield is movably driven by the flexible mechanical cable which is connected to and driven by the railroad switch distance amplification mechanism in the manner described below. Similar to the signal&#39;s shape, the vertically movable reflector blocking shield could be other shapes without deviating from the intent of the invention. 
     In use, when the switchpoints are in a nonswitching and therefore non-diverging position, the reflector blocking shield is lowered all the way and the upper green reflectors are visible. When the switchpoints are in the switching and therefore diverging position, the reflector blocking shield is raised all the way and the lower red reflectors are visible. Alternatively when the switchpoints are in a midpoint position, the reflector blocking shield automatically and without depending on electricity, defaults to a middle position thereby exposing a portion of both the upper red and lower green reflectors so as to indicate a dangerous, midpoint railroad switch position. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated, in which: 
         FIG. 1  is a perspective view of the cable driven railroad switch indicator system; 
         FIG. 2  is a plan view of a railroad switch distance amplifier mechanism along with a flexible mechanical cable. 
         FIG. 3  is a plan view of the cable driven railroad switch indicator system; 
         FIG. 4  is a top view of a signal with the top cover removed for clarity. 
         FIG. 5  is a detail view taken along the line  5 - 5  in  FIG. 4   
         FIG. 6A  is a side elevation view of the signal and flexible mechanical cable showing the reflector blocking shield in a midpoint position. 
         FIG. 6B  is a side elevation view of the signal and flexible mechanical cable showing the reflector blocking shield in a lowered position. 
         FIG. 6C  is a side elevation view of the signal and flexible mechanical cable showing the reflector blocking shield in a raised position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings more particularly by reference character and beginning with  FIG. 1 , reference numeral  10  refers to a railroad switch indicator for use with a railroad switch  16  for switching a railroad train from one track to another. 
     Railroad switch  16  normally comprises a pair of fixed outer stockrails  18 ,  20  and pair of inner switchrails  22 ,  24 . Inner switchrails  22 ,  24  have one end rigidly secured to the track bed and the opposite end terminating in laterally spaced switchpoints  26 ,  28  arranged for conjoint lateral movement between laterally spaced switching and nonswitching positions. A transverse bar  30  connects inner rails  22 ,  24  for moving switchpoints  26 ,  28  conjointly from one position to another. Transverse bar  30  may be manually operated, hydraulically or electrically powered by a conventional mechanism  32 . 
     As shown in  FIG. 1 , switchpoints  26 ,  28  are in nonswitching position with switchpoint  26  positioned against stationary left stockrail  18  and switchpoint  28  moved away from stationary right stockrail  20 . In nonswitching position, switchpoint  26  will direct a train entering switch  16  straight through the intersection via right stockrail  20  and switchrail  22  which tapers outward into a straight left rail past switch  16 . In a reverse position (not shown), both switchpoints are moved to the right with switchpoint  26  thus moved away from left stockrail  18  and switchpoint  28  moved to a position against right stockrail  20 . Switchpoint  28  is thus in a position to direct the train to the left via left stockrail  18  which curves to the left past switch  16 , and via right switchrail  28  which tapers outward to a curved right track past switch  16 . 
     With continuing reference to  FIG. 1 , switch  16  is lined against a train curving to the left. If a train runs through switch  16  from the curved section, switchpoints  26 ,  28  will be pushed into a mid position such that they contact neither left nor right stockrails  18 ,  20  and a train coming through switch  16  from bottom to top may derail if the operator depends on the signals associated with mechanism  32  for moving switch points  26 ,  28  if they falsely indicate that switch  16  remains lined for straight through travel. 
       FIG. 1  also shows a vertically elongated version of a signal  10  that has a plurality of reflectors of alternating colors so as to give the operator an indication of the condition of the track or the switch. This vertically elongated version of a railroad switch indicator is described and claimed in U.S. Pat. No. 8,695,925 and subsequent drawings show another signal  11 ; the basic colored signaling scheme between the elongated version  10  and the octagonal  11  version remain the same. 
     With continued reference to  FIG. 1  the elongated version signal  10  or octagonal signal  11  is motivated to vary its colored signals by a flexible mechanical cable  12  that transmits a mechanical push-pull force by movement of an flexible inner cable  42  relative to a stationary hollow outer cable housing  44 . This flexible cable allows the signal  10  or  11  to be positioned remotely from the railroad switch distance amplifier mechanism  14  so that the signal can be placed in a highly visible and easily serviceable location such as off to the side and/or in an elevated position relative to the railroad track. 
     As shown in  FIG. 2 , a railroad switch distance amplification mechanism is fixably mounted to the railroad track inside of outer stockrails  18 ,  20  using bolted mounting brackets  40 . An operator is attached to inner stockrails  22 ,  24 . As illustrated the operator includes a longitudinally extending arm  38  with an upwardly extending finger  41  attached via a bracket  36  to a transverse bar  30  connecting inner stockrails  22 ,  24 . The finger  41  engages first and second spaced apart linkage arms  86 ,  88  pivoted to a frame  90  and to a cross member  91 . The cross member  91  is adapted to apply a force between a pivoted end and an output end of a lever  39 . The finger  41  contact a first of linkage arms  86 ,  88  when the switchpoints  26 ,  28  are in nonswitching position and contacts a second of linkage arms  86 ,  88  when the switchpoints are in switching position. When the switchpoints  26 ,  28  are in mid position, finger  41  contacts neither of the linkage arms  86 ,  88 . With continuing reference to  FIG. 2 , the output end of lever  39  is attached to a clevis  43  which is attached to and therefore moves flexible inner cable  42  in relation to hollow cable outer housing  44  which is attached to fixed anchor point  47  on the frame  90 . Flexible mechanical cable  12  incorporates a provision for adjusting the cable tension and the end point relationship between hollow cable outer housing  44  relative to flexible inner cable  42  using an inline hollow bolt  45  passing though fixed anchor point  47  and therefore lengthens or shortens the hollow cable outer housing  44  relative to flexible inner cable  42 . The hollow bolt  45  is held in the desired position using locking nuts  42 . When finger  41  engages linkage arms  86 ,  88 , lever  39  moves a distance greater than the distance moved by switchpoints  26 ,  28 , pulling or pushing cable  12  by that amplified amount, thus increasing the sensitivity of the railroad switch indicator to movement of the switchpoints. 
       FIG. 3  is a plan view of an alternate embodiment of the cable driven railroad switch indicator system in which the railroad switch distance amplifier mechanism  14  is placed alongside of the railroad track as opposed to in between the tracks as shown in  FIG. 1  and  FIG. 2 . As shown in  FIG. 1  it shows railroad switch  16  for switching a railroad train from one track to another. 
     Similarly to  FIG. 1 , railroad switch  16  comprises a pair of fixed outer stockrails  18 ,  20  and pair of inner switchrails  22 ,  24 . Inner switchrails  22 ,  24  have one end rigidly secured to the track bed and the opposite end terminating in laterally spaced switchpoints  26 ,  28  arranged for conjoint lateral movement between laterally spaced switching and nonswitching positions. A transverse bar  30  connects inner rails  22 ,  24  for moving switchpoints  26 ,  28  conjointly from one position to another. Transverse bar  30  may be manually operated, hydraulically or electrically powered by a conventional mechanism  32  not shown in this view. 
     In this alternative embodiment, transverse bar  30  is attached to and moves a transverse extending arm  37  via bracket  36 . Similar to the previous switch indicator, a transverse extending arm  37  also has an upwardly extending finger  41 . The finger  41  engages linkage arms  86 ,  88  that comprise the railroad switch distance amplification mechanism  14 . When the finger  41  moves with the switchpoints, the amplification mechanism  14  moves the output lever arm  39  a distance greater than the distance moved by the finger  41  thereby increasing the sensitivity of the railroad switch indicator  11  to movement of the switchpoints  26  and  28 . The output end of is output lever arm  39  is attached to clevis  43  which is attached to and therefore moves flexible inner cable  42  in relation to hollow cable outer housing  44  which is stationarily attached to fixed anchor point  47 . 
     With continued reference to  FIG. 3  the octagonal version of the railroad switch indicator  11  is motivated to vary its colored signals by a flexible mechanical cable  12  that transmits a mechanical push-pull force by the movement of an flexible inner cable  42  relative to a stationary hollow outer cable housing  44 . This flexible cable allows the railroad switch indicator  11  to be positioned remotely from the railroad switch distance amplifier mechanism  14  so that the railroad switch indicator  11  can be placed in a highly visible and easily serviceable location such as off to the side and/or in an elevated position relative to the railroad track. 
       FIG. 4  is a top view of the octagonal signal  11  with the top cover  62  which is shown in  FIGS. 6A, 6B and 6C  removed for clarity.  FIG. 5  is a detail view taken along the line  5 - 5  in  FIG. 4 . 
     Referring to both  FIG. 4  and  FIG. 5 ; the signal is comprised of a octagonal shaped base plate  54  that has eight vertical flanges  56  rising upwards from it. Attached to each flange  56  is an upper green reflector  48  and lower red reflector  50 . Therefore the eight octagonally arranged vertical flanges  56  with reflectors  48  and  50 , when viewed from the side such as in  FIGS. 6A, 6B and 6C , serve to form an upper ring of green reflectors  58  and a lower ring of red reflectors  60  as shown in  FIGS. 6A, 6B and 6C . 
     With continuing reference to  FIG. 5 , the base plate  54  has two vertical spring bolts  64  rising upwards from it. Placed over each spring bolt  64  is a lower compression spring  66  and an upper compression spring  68 . The upper compression springs  68  are retained on the spring bolts  64  using washers  72  and hex nuts  74 . Sandwiched in between each lower spring  66  and upper spring  68  is a reflector shield base plate  70 . When the lower compression springs  66  and upper compression springs  68  are of equal size and strength they serve to position the reflector shield base plate  70  in a middle position relative to the base plate  54  and washers  72 . The reflector shield base plate is attached to outer tube  76  which is slidably mounted over inner tube  78 . Attached to outer tube  76  are four reflector shield cross plates  80  that protrude through the gaps  82  in the vertical flanges  56  as shown in  FIG. 6A . These reflector shield cross plates  80  are attached to a vertically movable octagonal shaped reflector blocking shield  52  that with up and down movement serves to selectively block all or portions of the upper ring of green reflectors  58  and/or the lower ring of red reflectors  60 . As per the above, because the lower compression springs  66  and upper compression springs  68  are of equal size and strength they serve to position the reflector shield base plate  70  and therefore the reflector blocking shield  52  in a middle position relative to the upper ring of green reflectors  58  and a lower ring of red reflectors  60  when no other forces are applied. 
     In reference to  FIG. 5  the other end of flexible mechanical cable  12  not attached to railroad switch distance amplifier mechanism  14  is attached to the signal base plate  54  via its fixed anchor point  84  Like the other end of the cable, this end of the mechanical cable  12  incorporates a provision for adjusting the cable tension and the end point relationship between flexible inner cable  42  and hollow cable outer housing  44  using an inline hollow bolt  45  which passes through fixed anchor point  84  and therefore lengthens or shortens the hollow cable outer housing  44  relative to flexible inner cable  42 . Similar to the other end of the cable the hollow bolt  45  is then held in the desired position using locking nuts  46 . This end of the flexible inner cable  42  is attached to outer shaft tube  76 . Therefore when the inner cable  42  is pushed or pulled by railroad switch distance amplifier mechanism  14  it causes the vertically movable octagonal shaped reflector blocking shield  52  to move up or down so as to selectively block all or portions of the upper ring of green reflectors  58  and/or the lower ring of red reflectors  60 . 
     In reference to  FIG. 6A , shown is a side elevation view of the signal  11  and flexible mechanical cable  12  showing the reflector blocking shield  52  in a midpoint position therefore showing portions of both the upper ring of green reflectors  58  and the lower ring of red reflectors  60 . Per the above this mid position is achieved when the railroad switch distance amplifier mechanism  14  neither pushes nor pulls on inner cable  42  due to the equalized spring pressure on both sides of the reflector shield base plate  70 . In this way the signal  11  defaults to its mid position so as to indicate a dangerous, midpoint railroad switch position. 
     In reference to  FIG. 6B , shown is a side elevation view of the signal  11  and flexible mechanical cable  12  showing the reflector blocking shield  52  in a lowered position and therefore showing only the upper ring of green reflectors  58 . Per the above this lowered position is achieved when the railroad switch distance amplifier mechanism  14  pulls on inner cable  42 . In this way the signal  11  indicates that the railroad switch  16  (not shown) is in a nonswitching position and therefore will direct a train entering switch  16  straight through the switchpoint. 
     In reference to  FIG. 6C , shown is a side elevation view of the signal  11  and flexible mechanical cable  12  showing the reflector blocking shield in a raised position and therefore showing only the lower ring of red reflectors  60 . Per the above this raised position is achieved when the railroad switch distance amplifier mechanism  14  pushes on inner cable  42 . In this way the signal  11  indicates that the railroad switch  16  (not shown) is in a diverging switching position and therefore will direct a train entering switch  16  to turn to a track other than straight when going through the switchpoint. 
     In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.