Production of magnetic sound tape

Claim 1

IN THE METHOD OF PRODUCING MAGNETIC SOUND-RECORDING AND SOUND-REPRODUCING TAPE BY PASSING A RELATIVELY LONG AND NARROW TAPE BASE OF THE MOVING PICTURE SOUND TYPE WITH MARGINAL SPROCKET HOLES, WHICH TAPE BASE HAS AN OBSTRUCTION THEREON, WHILE THE TAPE BASE IS UNDER TENSION, SUCCESSIVELY THROUGH A COATING ZONE AND A DRYING ZONE, ONE FLAT SURFACE OF THE TAPE BASE BEING COATED WITH A LAYER OF FREE-FLOWING MAGNETIC MATERIAL SUSPENDED IN A LIQUID VEHICLE WHILE MOVING THROUGH THE COATING ZONE AND THE COATING BEING DRIED WHILE MOVING THROUGH THE DRYING ZONE, THE IMPROVEMENT WHICH COMPRISES PROVIDING AND MAINTAINING IN THE COATING ZONE A GAP OF PREDETERMINED MINIMUM UNIFORM HEIGHT WIDER THAN THE THICKNESS OF THE TAPE BASE BETWEEN A BOTTOM SUPPORT FOR THE TAPE BASE AND A SUPERPOSED TRANSVERSE LIQUID BODY OF THE FREE-FLOWING MAGNETIC MATERIAL, MOVING THE TAPE BASE CONTAINING THE OBSTRUCTION THROUGH THE GAP WITH ITS BOTTOM SIDE IN SURFACE-TO-SURFACE CONTACT WITH THE TOP OF THE SUPPORT IN A GENERALLY HORIZONTAL DIRECTION AND ITS TOP SIDE NORMALLY OUT OF CONTACT WITH AND AT A PREDETERMINED MINIMUM DISTANCE BELOW THE LIQUID BODY OF MAGNETIC MATERIAL TO ASSURE A COATING OF PREDETERMINED THICKNESS ON THE TOP SIDE OF THE TAPE BASE, CONFINING THE APPLICATION OF THE COATING TO THE TOP SURFACE OF THE TAPE BASE BETWEEN THE SPROCKET HOLES THEREOF, INCREASING MOMENTARILY THE HEIGHT