Trough hatch cover and operating mechanism

Claim 1

A HATCH COVER AND OPERATING ARRANGEMENT FOR USE ON A COVERED HOPPER CAR COMPRISING AN UPSTANDING HATCH COAMING SURROUNDING AN OPENING FORMED IN A ROOF COVERING AN UPPER PORTION OF SAID CAR, SAID HATCH COAMING HAVING A CURLED UPPER EDGE FOR COOPERATING WITH A GASKET, A HATCH COVER MOUNTING SAID GASKET AND BEING ADAPTED TO CLOSE OFF SAID OPENING BY OVERLYING SAID COAMING, SAID HATCH COVER BEING FORMED FROM SEMICIRCULAR END SECTIONS JOINED TO OPPOSITE ENDS OF A STRAIGHT CENTER SECTION OF RECTANGULAR FORM, HINGE MEANS MOUNTING SAID HATCH COVER FOR PIVOTING MOVEMENT ADJACENT ONE SIDE OF SAID HATCH COAMING, SAID HINGE MEANS INCLUDING SPACED STRAP HINGE MEANS OVERLYING SAID HATCH COVER, AN OPERATING MEANS TO BIAS SAID HATCH COVER FROM AN OPEN AND CLOSED POSITION IN THE ABSENCE OF EXTERNAL FORCES, SAID OPERATING MEANS INCLUDING AN ELONGATED TORSION BAR, MEANS CLAMPING THE OPPOSITE ENDS OF SAID TORSION BAR TO SAID SPACED STRAP HINGE MEANS FOR ROTARY MOVEMENT THEREWITH, ROTARY STOP MEANS CLAMPED TO SAID TORSION BAR INTERMEDIATE THE ENDS THEREOF FOR ROTARY MOVEMENT THEREWITH AS SAID LATCH COVER IS MOVED FROM THE OPEN AND CLOSED POSITION, AND ANGULARLY SPACED SECOND STOP MEANS FIXED TO SAID ROOF AND IN THE PATH OF SAID ROTARY STOP MEANS AND POSITION TO APPLY A PREDETERMINED TORSION FORCE ON SAID TORSION BAR WHEN SAID HATCH OVER IS IN THE OPEN AND CLOSED POSITIONS.