Loose leaf binder

Claim 1

A LOOS LEAF BINDER HAVING BINDING MEANS CONNECTED BY FLEXIBLE PLASTIC POSTS REMOVABLY SECURED BY THEIR HEADS TO ONE OF THE BINDING MEANS AND A SLIDING LATCH IN THE OTHER BINDING MEANS TO RETAIN THE FREE ENDS OF THE POSTS, SAID BINDING MEANS COMPRISING A CHANNEL HAVING A FLOOR AND SIDE WALLS, EACH SIDE WALL HAVING AN INWARDLY EXTENDING FLANGE, WHEREIN THE IMPROVEMENT COMPRISES SAID FLANGE BEING U-SHAPED AND HAVING A MEDIAN SURFACE SPACED INWARDLY FROM THE ADJOINING SIDE WALL AND A FREE EDGE SPACED HORIZONTALLY FROM SAID SIDE WALL AND VERTICALLY FROM THE FLOOR, IN COMBINATION WITH THE REMOVABLE POST HAVING A HEAD WITH A SHORTER DIMENSION WHICH IS LESS THAN THE DISTANCE BETWEEN THE FLANGES, AND A LONGER DIMENSION SUBSTANTIALLY EQUAL IN LENGTH TO THE DISTANCE BETWEEN THE SIDE WALLS OF THE CHANNEL ADJACENT THE FREE EDGE OF THE FLANGE, SAID LONGER DIMENSION HAVING A TONGUE AT EACH END AND HAVING A PAIR OF VERTICAL WALLS ABOVE THE TONGUE SPACED APART BY A DISTANCE SUBSTANTIALLY EQUAL TO THAT BETWEEN THE MEDIAN WALLS OF THE FLANGES, WHEREBY WHEN THE HEAD IS LENGTHWISE OF THE CHANNEL THE POST HEAD CAN READILY BE PLACED IN OR REMOVED FROM THE CHANNEL, AND WHEN THE HEAD LIES CROSSWISE OF THE CHANNEL SAID VERTICAL WALLS ABOVE THE TONGUE COOPERATE WITH THE MEDIAN SURFACES OF THE USHAPED FLANGES, AND THE ENDS OF THE TONGUE LIE BETWEEN THE FLOOR AND FREE EDGES OF THE U-SHAPED FLANGES AND CONTACT SAID FREE EDGES, THEREBY LOCKING THE POST IN THE BINDING ELEMENT.