Integrated locking control and status indicator for manually operated railway switch stand

Abstract

The invention relates to a device to be integrated with to a manual switch stand, particularly for use in dark territory. The device secures the spindle of the switch stand against rotation, thereby preventing authorized throwing of the switches. The device also contains sensors that will clearly indicate to an external observer both the position of the switch points and the locked or unlocked status of the switch stand. A particular sequence of steps must be taken before an operator will be able to unlock the switch stand and throw the switch, and further steps are required before he can secure the switch stand and remove his key. The switch stand must therefore be left in a locked state, and it continuously indicates the status of the switch stand to a remote monitor.

1 . A rail switch stand comprising:
 an elongated spindle mounted for rotation about a vertical axis and wherein rotation of said spindle is adapted to cause actuation of a throw rod;   a lever for manually actuating rotation of said spindle, the plane of motion of said lever being spatially offset from said axis;   a plate lying substantially in a horizontal plane and being coupled to an intermediate portion of said spindle for co-axial rotation therewith, said plate comprising at least one engagement surface for engaging a locking bar, wherein engagement of said locking bar in said at least one engagement surface locks said spindle against rotation; and   a lock sensor for sensing when said locking bar is engaged in said engagement surface.   
   
   
       2 . The rail switch stand of  claim 1  further comprising an enclosure mounted about said intermediate portion of said spindle, said plate being disposed in said enclosure. 
   
   
       3 . The rail switch stand of  claim 1  wherein said at least one engagement surface comprises a notch in said plate. 
   
   
       4 . The rail switch stand of  claim 1  wherein said plate further comprises a second engagement surface, said at least one engagement surface corresponding to a first position of said throw rod and said second engagement surface corresponding to a second position of said throw rod. 
   
   
       5 . The rail switch stand of  claim 4  wherein each of said engagement surfaces comprises a notch. 
   
   
       6 . The rail switch stand of  claim 4  wherein said at least one engagement surface and said second engagement surface are disposed about said plate at 90 degrees of angular separation. 
   
   
       7 . The rail switch stand of  claim 1  further comprising a switch position sensor for sensing the rotational position of said plate, said rotational position corresponding to the position of said throw rod. 
   
   
       8 . The rail switch stand of  claim 7  further comprising an enclosure mounted about said intermediate portion of said spindle, said plate, said lock sensor and said switch position sensor all being disposed in said enclosure. 
   
   
       9 . The rail switch stand of  claim 8  wherein said switch position sensor comprises two contacts corresponding to two angularly displaced other contacts on said plate. 
   
   
       10 . The rail switch stand of  claim 7  wherein said switch position sensor comprises two contacts corresponding to two angularly displaced other contacts on said plate. 
   
   
       11 . The rail switch stand of  claim 1  further comprising a retractable stop member for retaining said locking bar in a first position corresponding to engagement with said engagement surface when a key is in a locking state. 
   
   
       12 . The switch stand of  claim 11  further comprising retention means to retain said key within said switch stand when said key is in a non-locking state. 
   
   
       13 . The rail switch stand of  claim 1  wherein said locking bar is vertically elongated and is displaceable into and out of engagement with said engagement surface by lateral movement. 
   
   
       14 . The rail switch stand of  claim 13  wherein said lateral movement of said locking bar is actuated by movement of a handle member. 
   
   
       15 . The rail switch stand of  claim 1 , further comprising:
 a second engagement surface disposed about said plate at 90 degrees of angular separation from said first engagement surface;   a switch position sensor for sensing the rotational position of said plate, said rotational position corresponding to the position of said throw rod;   said switch position sensor comprising two contacts corresponding to two angularly displaced other contacts on said plate.   
   
   
       16 . An integrated lock control and status indication device for a manually operated railway switch stand, comprising:
 a plate;   a locking member engageable with at least one engagement surface in said plate to prevent rotation of said plate;   a handle member to control engagement and disengagement of said locking member with said at least one engagement surface;   a lock means to maintain said locking member in engagement with said engagement surface until a matching key has been inserted; and   a first sensor to sense the engagement and disengagement status of said locking member.   
   
   
       17 . The device of  claim 16 , wherein said at least one engagement surface corresponds to a rail switch position of normal or reverse, and said locking member prevents rotation of said plate only if the rail switch is fully in a normal or reverse position. 
   
   
       18 . The device of  claim 17 , wherein said handle member can move into a locked position only when said locking member is engaged with said at least one engagement surface. 
   
   
       19 . The device of  claim 17 , wherein said lock means retains said key unless said locking member is engaged in said at least one engagement surface. 
   
   
       20 . The device of  claim 16 , wherein said engagement or disengagement status is communicated to an external notification device. 
   
   
       21 . The device of  claim 16 , further comprising a second sensor to sense the position of said plate and to provide an indication of a rail switch position of normal or reverse. 
   
   
       22 . The device of  claim 21  wherein said indication of a rail switch position is communicated to an external notification device. 
   
   
       23 . A manually operated rail switch stand comprising:
 a throw handle rotatably connected to a spindle, by which switch points may be controlled;   a plate through which said spindle passes, such that said plate and said spindle rotate in a coordinated manner;   a locking member that may engage at least one engagement surface in said plate to prevent rotation of said plate and said spindle;   a handle member to manually control engagement and disengagement of said locking member with said at least one engagement surface;   a lock means that maintains said locking member in engagement with said plate until a matching key has been inserted; and   a first sensor to monitor engagement and disengagement status of said locking member.   
   
   
       24 . The switch stand of  claim 23 , further comprising a second sensor to monitor the position of said plate and to provide an indication of a position of said switch points. 
   
   
       25 . The switch stand of  claim 23 , wherein said engagement or disengagement status is communicated to an external notification device. 
   
   
       26 . The switch stand of  claim 24  wherein said indication of a rail switch position is communicated to an external notification device. 
   
   
       27 . A method of operating a rail switch stand, comprising the sequential steps of:
 inserting a key to move a retractable stop member out of abutment with a locking member;   turning a handle member to disengage said locking member from a first engagement surface on a plate;   actuating a lever to rotate a spindle on which said plate is coaxially mounted, thereby rotating said plate and wherein rotation of said spindle causes rotation of a throw rod operatively connected to said lever; and   sensing when said locking member is disengaged from said first engagement surface through a first sensor means in operative communication with said locking member and thereby determining a status of said switch stand.   
   
   
       28 . The method of  claim 27  comprising the further step of signaling said status to an external notification device. 
   
   
       29 . The method of  claim 27  comprising the further step of sensing a position of said throw rod through a second sensor means in operative communication with said plate. 
   
   
       30 . The method of  claim 29  comprising the further step of signaling the position of said throw rod to an external notification device. 
   
   
       31 . A method of securing a rail switch stand, comprising the sequential steps of:
 moving a lever operatively connected to a throw rod and to an elongated spindle, such that said throw rod is in a reverse or normal position;   actuating a handle member to engage a locking member with an engagement surface on a plate mounted on an intermediate portion of said spindle;   sensing that said locking member is engaged with said first engagement surface with a sensor means;   applying a retractable stop member to a lateral portion of said locking member; and   removing a key from a lock means controlling said retractable stop member.   
   
   
       32 . The method of  claim 29  comprising the further step of locking said lever in place, when said throw rod is in said normal or reverse position. 
   
   
       33 . The method of  claim 31  comprising the further step of signaling that said locking member is engaged with said first engagement surface to an external notification device. 
   
   
       34 . The method of  claim 27  comprising the further step of sensing a position of said throw rod through a second sensor means in operative communication with said plate. 
   
   
       35 . The method of  claim 29  comprising the further step of signaling the position of said throw rod to an external notification device.