Filter for high velocity gas streams

Claim 1

IN A FILTER UNIT FOR INSERTION INTO THE NOSE CONE OF A SUPERSONIC AIR SAMPLING ROCKET, THE COMBINATION COMPRISING A CELLULOSE FIBER MEDIUM MATTED TOGETHER ON A SCRIM BACKING, SAID FIBERS HAVING A MEAN DIAMETER IN THE RANGE OF ONE MICRON AND A LENGTH OF AT LEAST ONE MILLIMETER, SAID MATTED FIBERS HAVING A MEAN DENSITY OF ABOUT 12.75 GRAMS PER SQUARE CENTIMETER, A THIN COATING OF STEARIC ACID ON SAID FIBERS, SAID ACID BEING EVENLY DISPOSED THEREON IN A QUANTITY CONSISTING OF 15 TO 20% BY WEIGHT OF THE WEIGHT OF SAID FIBERS, FRONT AND BACK PROTECTIVE LOOSE WEAVE FABRIC COVERS COMPRESSED AGAINST SAID FIBERS, THREAD STITCHED THEREBETWEEN TO SECURE ALL PORTIONS OF SAID MATTED FIBERS AND COVERS TO FORM A FILTER ASSEMBLY, SAID STICHING FORMING A ZIG-ZAG SPIRAL PATTERN IN THE FORM OF A SINE WAVE HAVING AN AMPLITUDE EQUAL TO TWICE THE WAVE LENGTH, AND MEANS FOR RETAINING SAID FILTER ASSEMBLY WITHIN AN OPEN FRAME ADAPTED TO BE DISPOSED WITHIN AN AIR FLOW CHANNEL.