Restraint assembly for the hopper door actuator of a rapid discharging railroad hopper car

In a railroad hopper car of the type having a longitudinal center sill of substantially inverted U-shape, a plurality of hopper doors arranged in opposed pairs and swingable between a closed position and a downwardly depending open position, and door-means comprising a fluid operated cylinder mounted above said center sill and a door-actuating beam mounted beneath said center sill, operatively connected to said hopper doors, and having an upwardly directed extension passing through a longitudinal slot in the upper surface of said center sill, said cylinder having a piston rod connected to said door-actuating beam extension above said center sill, said piston rod and said door-actuating beam being longitudinally shiftable by said cylinder between a retracted door-closing position and an extended door-opening position, the improvement comprising a restraint assembly for said door actuating means to prevent unintentional shifting of said piston rod and said door-actuating beam from said retracted door-closing position to said extended door-opening position due to inertia, said restraint assembly comprising a first bracket mounted on the upper surface of said center sill, a shaft rotatively mounted in said bracket and extending transversely of said center sill, a lever non-rotatively mounted on said shaft, a spring assembly having first and second ends, said lever having a free end pivotally joined to said first end of said spring assembly, a second bracket affixed to the upper surface of said center sill, said second end of said spring assembly being pivotally mounted to said second bracket, the distance between said shaft and said pivotal mounting of said second end of said spring assembly being less than the combined length of said lever and said spring assembly in extended condition, one end of said shaft extending beyond said first bracket and having a notch formed therein, said notch having first and second sides constituting first and second abutment surfaces, said door actuating beam extension having a laterally extending lug mounted thereon said pivotal attachment of said free end of said lever and said first end of said spring assembly lying in a first over-center position above an imaginary line drawn between the axial center of said shaft and the center of said pivotal mounting of said second end of said spring assembly when said restraint assembly is in its restraining condition and said piston rod and door-actuating beam are in their retracted door-closing position, said lug on said door-actuating beam extension being so positioned as to contact said first abutment surface of said notch to prevent longitudinal shifting of said door-actuating beam to open said hopper doors due to inertia, said shaft being rotatable by said abutment of said lug and said first abutment surface when said piston rod is shifted by said cylinder toward said door-opening position to rotate said lever against the action of said spring assembly until said pivotal connection between said free end of said lever and said first end of said spring assembly passes to a second over-center position below said imaginary line and said restraint assembly achieves a non-restraining condition wherein said first abutment surface of said shaft notch is no longer in position to be abutted by said door-actuating means lug and said door-actuating means is free to shift to its door-opening position, said door-actuating means lug being so positioned as to engage said second abutment surface of said shaft notch to rotate said shaft and return said restraint assembly to its restraining condition with said pivotal connection between said lever free end and said spring assembly first end being in said first over-center position when said cylinder is actuated to shift said piston rod and said door-actuating means to said door-closing position.