Folding door

Claim 1

A FOLDING DOOR STRUCTURE FOR A DOOR OPENING, AN UPPER TRACK MEMBER FIXEDLY MOUNTED TO THE HEADER IN THE DOOR OPENING AND EXTENDING BETWEEN THE JAMS THEREOF, SAID TRACK MEMBER BEING FORMED WITH A ROLLER RECEIVING SLOT HAVING INWARDLY EXTENDING SIDE FLANGES EXTENDING IN SPACED PARALLEL RELATION, A LOWER TRACK MEMBER FORMED WITH A ROLLER RECEIVING SLOT AND BEING FIXEDLY MOUNTED TO THE SILL OF THE OPENING AND EXTENDING BETWEEN THE JAMS THEREOF, A PAIR OF FIRST AND SECOND PANEL MEMBERS HINGEDLY JOINED ALONG THEIR VERTICAL EDGES AND BEING OF VERTICAL DIMENSION OF INSERTION IN SAID OPENING BETWEEN SAID TRACK MEMBERS, THE FIRST OF SAID PANELS BEING PROVIDED WITH VERTICALLY ALIGNED UPPER AND LOWER PINTLE PINS EXTENDING FROM THE UPPER AND LOWER EDGES OF SAID FIRST PANEL IN SPACED RELATION TO SAID HINGED JOINT, THE OUTER ENDS OF SAID PINS BEING JOURNALLED IN SAID UPPER AND LOWER TRACK MEMBERS, SAID UPPER PRINTLE PIN BEING AXIALLY SLIDABLE IN SAID FIRST PANEL, SPRING MEANS ACTING ON SAID PIN TO YIELDINGLY URGE THE SAME UPWARDLY, SAID LOWER PINTLE PIN HAVING A STOP COLLAR MEMBER ADJUSTABLE AXIALLY OF THE PIN FOR ENGAGING SAID FIRST PANEL FOR THE SUPPORT OF SAID FIRST PANEL BY SAID LOWER PINTLE PIN, UPPER AND LOWER ROLLER PINS MOUNTED IN SAID SECOND PANEL OF SAID PAIR IN SPACED RELATION TO SAID HINGED JOINT, SAID LOWER ROLLER PIN HAVING A ROLLER JOURNALLED THEREON FOR MOVEMENT ALONG THE SLOT IN SAID LOWER TRACK MEMBER, SAID UPPER ROLLER PIN HAVING A ROLLER JOURNALLED THEREON FOR MOVEMENT ALONG THE FLANGES OF SAID UPPER TRACK MEMBER, MEANS RESTRAINING DOWNWARD MOVEMENT OF SAID UPPER ROLLER PIN RELATIVE TO THE ROLLER JOURNALLED THEREON, SAID UPPER AND LOWER ROLLER PINS BEING AXIALLY SLIDABLE IN SAID SECOND PANEL.