Drying hood with movable plenum construction

Claim 1

IN A DRIER FOR DRYING TRAVELING FIBROUS WEBS IN THE MAKING OF PAPER AND IN COMBINATION WITH A DRYING CYLINDER HAVING A WEB TRAINED THEREABOUT, A HOOD EXTENDING ALONG AND PARTIALLY ABOUT SAID DRYING CYLINDER AND SPACED THEREABOVE, A PLENUM WITHIN SAID HOOD HAVING CLOSED ENDS WITH A TOP WALL AND AN ARCUATE BOTTOM WALL GENERALLY CONFORMING TO SAID DRYING CYLINDER, AIR IMPINGEMENT ORIFICES IN THE BOTTOM WALL OF SAID PLENUM, EXHAUST PASSAGEWAYS EXTENDING THROUGH SAID BOTTOM WALL AND SAID TOP WALL OF THE PLENUM AND COMMUNICATING WITH THE INTERIOR OF SAID HOOD, AN AIR INLET IN SAID HOOD THROUGH WHICH AIR IS PASSED INTO SAID HOOD, AN AIR OUTLET LEADING FROM SAID HOOD, AN AIR SUPPLY DUCT MEANS ADAPTED TO BE ADJUSTABLY POSITIONED IN REGISTRATION WITH SAID AIR INLET, SAID AIR ING COMMUNICATION BETWEEN SAID AIR INLET, SAID AIR SUPPLY DUCT MEANS AND SAID PLENUM, SAID AIR SUPPLY DUCT MEANS BEING FIXED TO SAID PLENUM FOR MOVEMENT THEREWITH, MEANS FOR SEALING SAID AIR SUPPLY DUCT MEANS TO SAID AIR INLET, MEANS FOR RAISING SAID PLENUM AND AIR SUPPLY DUCT MEANS RELATIVE TO SAID HOOD TO AFFORD ACCESS TO THE DRYING CYLINDER AND WEB TRAINED THEREABOUT, SAID SEALING MEANS BETWEEN SAID AIR INLET AND SAID AIR SUPPLY DUCT MEANS MOVING OUT OF SEALING ENGAGEMENT WITH SAID AIR INLET TO SAID HOOD UPON THE RAISING OF SAID PLENUM RELATIVE TO SAID HOOD AND THE MOVEMENT OF SAID AIR SUPPLY DUCT MEANS PARTIALLY OUT OF REGISTRY WITH SAID AIR SUPPLY DUCT MEANS PARTIALLY TION OF AIR INTO SAID HOOD OUT THROUGH SAID EXHAUST PASSAGEWAYS AND TO SCAVENGE SAID EXHAUST PASSAGEWAYS FROM DEBRIS LODGING THEREIN.