Air jet cleaning and nozzle for use therefor

Claim 2

A MACHINE FOR CLEANING AROUSTICAL TILE HAVING A PLURALITY OF CAVITY-TYPE SOUND ABSORBING HOLES THEREIN, SAID MACHINE COMPRISING AN AIR TANK, A PLURALITY OF STRAIGHT-JET PRODUCING NOZZLES DISPOSED IN ONE FACE OF SAID TANK, SAID TANK HAVING SUFFICIENT VOLUME TO PROVIDE SUBSTANTIALLY EQUAL AIR PRESSURE TO ALL SAID NOZZLES, BELT SHOES EXTENDING THROUGH THE CLEANING PORTION OF SAID MACHINE, ENDLESS BELTS DISPOSED IN SAID SHOES FOR SUPPORTING AND ADVANCING SAID TILES THROUGH SAID MACHINE AND FOR POSITIONING SAID TILE HOLES SUCCESSIVELY OVER RESPECTIVE NOZZLES, SAID SHOES AND THUS SAID BELTS BEING LATERALLY SPACED APART AND DISPOSED UNDER THE EDGES OF TILES BEING SUPPORTED THEREON, AND SPACED FROM SAID HOLES OF TILES SUPPORTED THEREON, AND MEANS FOR RESTRAINING SAID TILES AGAINST MOVEMENT AWAY FROM SAID NOZZLES, SAID NOZZLES BEING CONSTRUCTED TO PRODUCE A STRAIGHT JET OF AIR HAVING A DIAMETER LESS THAN HALF THE DIAMETER OF SAID HOLES, TO PROVIDE A JET CAPABLE OF ENTERING SAID HOLES ADJACENT THE PERIPHERY OF SAID HOLESAND FOLLOW A SUBSTANTIALLY U-SHAPED PATH INTO AND THENCE OUT OF SAID HOLES IN A CONTINUOUS, SUBSTANTIALLY UNIFORM STREAM.