摘要 |
<p>RAILROAD VEHICLE An enclosed railroad hopper car has a valve that controls the discharge of the commodity it carries. The valve is opened and closed by an operating mechanism that is subjected to vibration and inertial forces during transit. This can jar open the valve. A cap for the discharge hopper outlet opening interlocks with the valve operating mechanism when the valve is closed so as to prevent the valve from opening. The cap is held in its open position by a trap that prevents it from swinging closed while -the car is being unloaded</p> |