Coil spring rail brake

Abstract

A rail brake includes a rigid enclosure which mounts under a crane so as to dispose the base end of the enclosure over and adjacent a rail. A top plate is mounted underneath the upper end of the enclosure. A spring carriage is mounted for vertical translation within the enclosure, beneath the top plate. Springs are mounted between the spring carriage and the top plate so that the springs are compressed when the spring carriage is elevated. A brake shoe is mounted under the carriage. Actuators are mounted between the spring carriage and the base end of the enclosure. Extension of the actuators compress the springs and elevate the brake shoe from the rail. Retraction allows the springs to drive the brake shoe against the rail. An opening in the enclosure allows replacement of the springs and actuators. Elevation of the brake shoe provides for its inspection and maintenance.

1 . A rail brake for a rail-mounted machine mounted for translation along a rail, said rail brake comprising:
 a rigid enclosure having an upper end and opposite base end rigidly mounted oppositely to said upper end, wherein said upper end is adapted for mounting to the rail-mounted machine so as to dispose said base end over and adjacent the rail,   a top plate mounted underneath, spaced apart from and substantially parallel to, said upper end so as to define a gap between said upper end and said top plate.   a spring carriage mounted for vertical translation within said enclosure, beneath said top plate, between an elevated position and a lowered position,   at least one spring mounted between said spring carriage and said top plate, said at least one spring compressed when said spring carriage is in said elevated position and decompressed when said spring carriage is in said lowered position,   at least one brake shoe mounted under said carriage so as to be oppositely disposed on said carriage relative to said at least one spring,   at least one selectively actuable actuator mounted between, so as to bear opposite ends thereof against, said spring carriage and said base end of said enclosure respectively, said at least one actuator actuable between extended and retracted positions wherein, in said extended position, said spring carriage is in said elevated position and said at least one brake shoe is correspondingly retracted upwardly, and wherein, in said retracted position,   said spring carriage is in said lowered position and said at least one brake shoe is correspondingly lowered so as to be urged into frictional engagement against the rail.   
     
     
         2 . The brake of  claim 1  wherein said at least one spring is at least one helical coil spring, and further comprising an elongate caging member, said caging member having opposite first and seconds ends, said member mounted to said spring carriage at said first end of said member and extending substantially parallel to said at least one spring, said second end of said member journalled in an aperture in said top plate, wherein said second end of said member is free to translate vertically in said gap as said spring carriage translates correspondingly within said enclosure so as to translate simultaneously and correspondingly therewith and so that said second end of said member protrudes into a spring-caging position in said gap when said spring carriage is in said elevated position, a selectively releasable lock selectively releasable locking said second end of said caging member in said spring-caging position whereby translation of said caging member and said spring carriage is immobilized when said second end is locked by said lock. 
     
     
         3 . The brake of  claim 2  wherein said enclosure includes sides extending between said upper end and said base end, and wherein at least one of said sides is open for removal of said spring carriage, said top plate, said at least one spring and/or said at least one actuator therethrough. 
     
     
         4 . The brake of  claim 3  wherein said at least one brake shoe is removable when said spring carriage is in said elevated position. 
     
     
         5 . The brake of  claim 4  wherein said carriage includes at least one bearing member and wherein said at least one actuator bears against said at least one bearing member. 
     
     
         6 . The brake of  claim 5  wherein said carriage translates a brake set distance between said elevated and lowered positions, and wherein said at least one actuator actuates a corresponding actuation distance between said extended and retracted positions. 
     
     
         7 . The brake of  claim 6  wherein said lock includes a latch member and wherein said caging member includes a latch receiver for releasably holding said latch member when said caging member is in said spring-caging position. 
     
     
         8 . The brake of  claim 7  wherein said at least one actuator also selectively elevates said carriage to an unlocking position which is further elevated above said elevated position so as to unload a spring force load applied to said latch member by said latch receiver, wherefrom said latch member is removable from said latch receiver. 
     
     
         9 . The brake of  claim 8  wherein said latch member includes a fork and wherein said latch receiver includes a lip on said caging member. 
     
     
         10 . The brake of  claim 9  wherein said lip is a substantially annular lip. 
     
     
         11 . The brake of  claim 10  wherein said lip is formed by a collar on said caging member. 
     
     
         12 . The brake of  claim 9  wherein said latch member is elongate and mounted substantially horizontally for horizontal translation into engagement under said lip. 
     
     
         13 . The brake of  claim 7  further comprising at least one spacer defining a vertical separation distance within said gap between said upper end and said top plate. 
     
     
         14 . The brake of  claim 13  wherein said separation distance is substantially equal to a translation distance of said spring carriage between said lowered position and said elevated position. 
     
     
         15 . The brake of  claim 14  wherein said separation distance is substantially equal to a translation distance of said carriage between said lowered position and said unlocking position when said at least one caging member is further elevated to allow unlocking of said latch. 
     
     
         16 . The brake of  claim 15  wherein said at least one spring is a pair of helical coil springs and wherein said at least one caging member is a pair of elongate shafts wherein each shaft of said pair of elongate shafts is journalled through a corresponding spring of said pair of helical coil springs. 
     
     
         17 . The brake of  claim 16  wherein said latch member includes a fork and wherein said latch receiver includes a lip on said caging member. 
     
     
         18 . The brake of  claim 17  wherein said at least one bearing member includes a pair of substantially oppositely disposed bearing members extending orthogonally relative to said pair of helical coil springs, wherein said at least one actuator is a corresponding pair of actuators extending substantially parallel to said pair of helical coil springs. 
     
     
         19 . The brake of  claim 18  wherein said at least one brake shoe is mounted under said carriage substantially equi-distant between said pair of helical coil springs so as to substantially evenly distribute a downward spring force of said each spring to said at least one brake shoe.