Hatch cover and locking structure

摘要

The hatch of a lading container, such as the hopper of a covered hopper car, is sealed by a hatch cover having a locking arrangement which prevents the hatch cover from being blown open by pressure within the hopper when the locking arrangement is unlocked. An over-center locking arm has two spaced catches which co-act with two latches on a latching arrangement to selectively provide a sealed, a pressure blow-off, and a hatch open position. A rotative adjustment is provided to enable adjustment of the sealing pressure of the hatch cover on the hatch.