Stock inlet for paper making machines and the like

Claim 1

A STOCK INLET FOR PAPER-MAKING MACHINES AND THE LIKE, COMPRISING A CLOSED HEADBOX HAVING SPACED APART ENTRANCE MEANS AND DISCHARGE MEANS FOR THE PASSAGE OF A FLOW OF STOCK THROUGH SAID HEADBOX AND CONTAINING AN AIR CUSHION UNDER PRESSURE ABOVE THE LEVEL OF THE STOCK, AN OVERFLOW EDGE DISPOSED INSIDE SAID HEADBOX SO THAT FOAM FORMED ON THE FLOWING STOCK IN SAID HEADBOX, TOGETHER WITH SMALL QUANTITIES OF STOCK, IS CARRIED OVER SAID OVEFLOW EDGE AND IS THUS PREVENTED FROM ENTERING SAID DISCHARGE MEANS, GUTTER MEANS ASSOCIATED WITH SAID OVERFLOW EDGE FOR COLLECTING EHE OVERFLOWING FOAM AND STOCK, SAID GUTTER MEANS BEING DISPOSED ON THE FRONT WALL OF SAID HEADBOX, DRAIN PIPE MEANS FOR DRAINING THE COLLECTED FOAM AND STOCK FROM SAID GUTTER MEANS, AND AN OVERHEAD TANK CONTAINING A LEVEL OF STOCK, SAID DRAIN PIPE MEAND BEING U-SHAPED AND CONNECTED TO SAID OVERHEAD TANK, THE LEVEL OF STOCK IN SAID OVERHEAD TANK BEING ABOVE THE LEVEL OF SAIS STOCK FLOWING THROUGH SAID HEADBOX, SO THAT THE PRESSURE IN SAID DRAIN PIPE MEANS CORRESPONDING TO THE GEODETIC HEAD OF SAID STOCK LEVEL IN SAID OVERHEAD TANK ABOVE SAID LEVEL OF STOCK IN SAID HEADBOX IS AT LEAST EQUAL TO THE HEAD OF STOCK CORRESPONDING TO THE PRESSURE ON SAID AIR CUSHION IN SAID HEADBOX.