Hole detector having logic circuitry for seam skipping

Claim 1

APPARATUS FOR DETECTING FLAWS IN FABRIC PASSING ALONG A FEED AXIS, THE FABRIC HAVING TRANSVERSELY SPANNING SEAMS SPACED ALONG SAID AXIS CAUSING NEEDLE HOLES ADJACENT THE SEAMS WHICH MUST BE DISTINGUISHED FROM HOLE FLAWS, COMPRISING A PLURALITY OF DETECTOR HEADS, EACH SENSING A DETECTOR ZONE AT THE FABRIC AND PRODUCING A DETECTOR SIGNAL WHEN A HOLE OCCURS IN ITS RESPECTIVE DETECTOR ZONE, SAID DETECTOR HEADS BEING ARRANGED IN SIDE-BY-SIDE RELATION ALIGNED ALONG A TRANSVERSE AXIS RELATIVE TO THE FEED AXIS WHEREBY THEIR DETECTOR ZONES COLLECTIVELY SPAN THE WIDTH OF THE FABRIC, FIRST AND SECOND CHANNEL AMPLIFIERS, EACH HAVING MEANS FOR PRODUCING A CHANNEL SIGNAL RESPONSIVE TO DETECTOR SIGNALS FROM A SELECTED GROUP OF SAID HEADS WHICH CHANNEL SIGNAL PERSISTS UNTIL RESTS, MEANS CONNECTING SAID FIRST AND SECOND CHANNEL AMPLIFIERS TO TWO DIFFERENT GROUPS OF SAID DETECTORS HEADS TO RENDER THE AMPLIFIERS RESPONSIVE TO HOLES IN TWO RESPECTIVE REGIONS OF THE FABRIC SPACED APART TRANSVESELY OF THE FABRIC FEED PATH, OUTPUT MEANS FOR PROVIDING AN OUTPUT SIGNAL SIGNIFYING HOLE FLAW DETECTION, TIME DELAY MEANS RESPONSIVE TO A CHANNEL SIGNAL FROM EITHER OF SAID CHANNEL AMPLIFIERS TO ACTIVATE SAID OUTPUT MEANS TO PRODUCE SAID OUTPUT SIGNAL A SELECTED TIME DELAY INTERVAL AFTER OCCURENCE OF SAID CHANNEL SIGNAL, AND MEANS RESPONSIVE TO A CONCURRENT PRODUCTION OF CHANNEL SIGNALS BY BOTH SAID CHANNEL AMPLIFIERS INDICATING DETECTION OF HOLES IN THE REGIONS SENSED BY BOTH OF SAID GROUPS OF DETECTOR HEADS IN TIME RELATIONSHIPS CHARACTERISTIC OF SEAM NEEDLE HOLES TO DISABLE SAID OUTPUT MEANS FROM PRODUCING AN OUTPUT SIGNAL BEFORE COMPLETION OF SAID TIME DELAY INTERVAL.