Refrigerated cabinet and defrosting means

Claim 1

IN A REFRIGERATED CABINET HAVING AN ENCLOSED STORAGE SPACE WITH AN ACCESS OPENING IN ONE WALL COMMUNICATING THE INTERIOR OF THE STORAGE SPACE WITH THE AMBIENT ATMOSPHERE, ADJACENT INNER AND OUTER OUTLET NOZZLES EXTENDING CONTINUOUSLY ACROSS ONE SIDE OF THE ACCESS OPENING AND CORRESPONDING INLET MEMBERS EXTENDING CONTINUOUSLY ACROSS THE OPPOSITE SIDE OF THE ACCESS OPENING, INNER AND OUTER PASSAGES COMMUNICATING WITH THE INLET MEMBERS AND THE INNER AND OUTER OUTLET NOZZLES RESPECTIVELY, MEANS FOR CAUSING STREAMS OF AIR TO FLOW THROUGH SAID PASSAGES FROM THE INLETS TO THE OUTLET NOZZLES AND FROM THE OUTLET NOZZLES AS AIR PANELS MAKING UP AN AIR CURTAIN FLOWING CONTINUOUSLY ACROSS THE ACCESS OPENING TO THE INLET MEMBERS FOR RECIRCULATION THROUGH THE PASSAGES, REFRIGERATION MEANS IN THE INNER PASSAGE FOR REFRIGERATION OF THE STREAM OF AIR FLOWING THERETHROUGH WHEREBY THE INNER AIR PANEL OF THE AIR CURTAIN COMPRISES A COLD AIR PANEL, PORTS WITHIN SAID INNER PASSAGE BEFORE AND BEYOND SAID REFRIGERATION MEANS, MEANS COMMUNICATING SAID PORTS WITH THE AMBIENT ATMOSPHERE, AND MEANS SHIFTABLE IN SAID INNER PASSAGE AND ASSOCIATED WITH EACH OF SAID PORTS FOR MOVEMENT BETWEEN UNBLOCKING POSITION TO BLOCK SAID PORTS AND FREE SAID PASSAGES TO PERMIT NORMAL FLOW OF THE COLD AIR STREAM CONTINUOUSLY THROUGH SAID INNER PASSAGE AND BLOCKING POSITION FOR BLOCKING SAID PASSAGE AND FREEING SAID PORTS FOR COMMUNICATION WITH THE AMBIENT ATMOSPHERE FOR FLOW OF AMBIENT AIR INTO SAID PASSAGE, THROUGH SAID REFRIGERATION MEANS, AND THEN OUT OF SAID PASSAGE FOR DEFROSTING THE REFRIGERATION MEANS.