Acoustic type folding door

Claim 1

IN AN ACCORDION TYPE FOLDING DOOR HAVING A PAIR OF END POSTS THAT DEFINE OPPOSITE VERTICAL END EDGES OF THE DOOR, UPPER AND LOWER EXTENSIBLE AND COLLAPSIBLE LAZYTONGS CONNECTING SAID POSTS, FOLDABLE COVER MEANS DISPOSED ALONG OPPOSITE SIDES OF SAID LAZYTONGS AND CONNECTED AT OPPOSITE ENDS TO THE RESPECTIVE POSTS, FLEXIBLE SEALING SKIRTS ATTACHED TO AND PROJECTING FROM THE UPPER AND LOWER EDGES OF THE COVER MEANS, EACH COVER MEANS INCLUDING A PLURALITY OF VERTICALLY ELONGATED CLOSELY SIDE-BY-SIDE DISPOSED RELATIVELY WIDE AND RELATIVELY NARROW SLATS ALTERNATELY ARRANGED AND PIVOTED TOGETHER BY MEANS INCLUDING INNER AND OUTER FLEXIBLE SHEETS ADHERED TO OPPOSITE FACES OF EACH OF THE SLATS, MEANS SECURING EVERY OTHER ONE OF SAID NARROW SLATS TO INTERMEDIATE POINTS OF EACH LAZYTONGS, EACH OF SAID WIDE SLATS BEING A SUBSTANTIALLY FLAT SHEET-LIKE STRUCTURE, AND VERTICALLY EXTENDED PADS OF LOW DENSITY RESILIENTLY COMPRESSIBLE FIBROUS SOUND SINSULATING MATERIAL MOUNTED EXTERIORLY IN FULL SURFACED FLUSH CONTACTING RELATION AGAINST THE INNER COVER SHEETS AT LOCATIONS OVERLYING AND SUBSTANTIALLY MASKING THE WIDE SLATS, SAID PADS BEING OF A THICKNESS SOMEWHAT GREATER THAN ONE HALF THE WIDTH OF THE NARROW SLATS TO INCRASE THE FREQUENCY SOUND ISOLATING CHARACTERISTICS OF THE DOOR BY AT LEAST 4 DB AND TO UNDERGO YIELDABLE COMPRESSION WHEN THE DOOR IS FOLDED TO MAINTAIN SUBSTANTIALLY THE SAME STACKING RATIO.