Patent ID: 8485110

Claim:
An apparatus for controlling discharge of materials from a railcar having a wheeled frame defining a longitudinal axis for said car and a hopper carried on said frame, with said hopper defining a longitudinally disposed discharge opening, and with said railcar having a door mounted to said hopper for pivotal movement between an open position and a closed position relative to said discharge opening, said apparatus comprising: an operating shaft carried by said car for rotation about a fixed axis; a drive operably coupled between said door and said operating shaft for causing said door to move from the closed position toward the open position in response to rotation of said operating shaft in a first rotational direction, with said drive including a rotary lost motion connection for allowing said door to freely pivot toward the open position during collapsing movement of said lost motion connection and after said operating shaft has been rotated a predetermined amount to open said door, with said lost motion connection limiting the forces acting on said operating shaft as a result of the gravitational effects said materials have acting on the door as said door moves from the closed position toward an open position.