Loose leaf binder

Claim 1

A LOOSE LEAF BINDER COMPRISING A TOP AND BOTTOM POST RETAINING MEMBER, SAID POST RETAINING MEMBERS HAVING A PLURALITY OF APERTURES, EACH OF SAID APERATURES BEING ALIGNED VERTICALLY WITH AN APERTURE OF SAID OTHER MEMBER, A FLEXIBLE SHEET RETAINING POST EXTENDING THROUGH EACH OF SAID PAIRS OF VERTICALLY ALIGNED APERTURES, EACH OF SAID POSTS HAVING AN ENLARGED HEAD ADJACENT THE LOWER SURFACE OF SAID BOTTOM POST RETAINING MEMBER, SAID LOWER SURFACE BEING CONCAVE, SAID POST HEADS BEING EACH DISPOSED BETWEEN EDGE PORTIONS OF ENLARGED THICKNESS DEPENDING BELOW THE PLANE OF SAID POST HEADS, SAID TOP POST RETAINING MEMBER HAVING A LONGITUDINAL RECESS IN ITS UPPER SURFACE, A GROOVE EXTENDING LATERALLY FROM EACH LONGITUDINAL EDGE OF SAID RECESS ALONG THE ENTIRE LENGTH OF SAID RECESS INTERMEDIATE ITS DEPTH, A PAIR OF TOP COVER PLATES FITTING IN SAID RECESS IN LONGITUDINAL ALIGNMENT, A LATERAL FLANGE ALONG EACH LONGITUDINAL EDGE OF SAID COVER PLATES, SAID FLANGES BEING SLIDABLE IN SAID GROOVES, A LIP EXTENDING DOWNWARDLY FROM THE OUTER END OF EACH OF SAID TOP COVER PLATES TO FACILITATE SLIDING MOVEMENT THEREOF, A STOP MEMBER ADJACENT EACH END OF SAID RECESS, AND A TAB FOLDED INWARDLY AGAINST THE UNDERSIDE OF EACH OF SAID TOP COVER PLATES AT THE INNER END THEREOF, THE FREE END OF EACH OF SAID TABS PROVIDING A SHOULDER ADAPTED TO COOPERATE WITH EACH OF SAID STOP MEMBERS TO PREVENT REMOVAL OF SAID TOP COVER PLATES FROM SAID RECESS.