Gate valve construction

Claim 1

IN A GATE VALVE, A MAIN BODY PART THAT IS SUBSTANTIALLY RECTANGULAR IN SECTION AND CONSISTING OF SUBSTANTIALLY FLAT PARALLEL END WALLS JOINED AT THEIR LONGITUDIANL EDGES BY SIDE WALLS, THE END WALLS HAVING ALIGNED OPENINGS THEREIN FOR FLOW PASSAGES, AT LEAST ONE PAIR OF REINFORCING RIBS EXTENDING LATERALLY ACROSS THE END WALLS ON OPPOSITE SIDES OF THE BODY, FLAT SIDE PLATES EXTENDING ACROSS THE SIDE WALLS OF THE BODY AND BEYOND THE OUTER FACES OF SAID END WALLS WITH THE PLANES OF THEIR FACES SUBSTANTIALLY PARALLEL TO THE OUTER SURFACES OF SAID SIDE WALLS, SAID SIDE PLATES BEING DIRECTLY ATTACHED TO THE EXTREMITIES OF THE RIBS AND TO SAID BODY, SAID RIBS HAVING EDGE PORTIONS DISPOSED ADJACENT SAID END WALLS TO RESIST OUTWARD DEFLECTION OF THE SAME, THE RIBS BEING PERPENDICULAR TO THE PLANES OF THE SIDE PLATES AND TO THE END WALLS OF THE BODY.