Binding for books

Claim 1

A PERMANENTLY BOUND BOOK HAVING A BINDING FOR THE LEAVES THEREOF COMPRISING A SPINE, A PAIR OF FLANGES ALONG OPPOSITE SIDES THEREOF AND SOLID BINDING POSTS EXTENDING FROM ONE OF SAID FLANGES TOWARD THE OTHER AND HAVING HEADS, SAID HEADS BEING OF LESS DIAMETER THAN SAID POSTS, SAID SPINE, FLANGES AND BINDING POSTS BEING INTEGRAL AND FORMED OF PLASTIC MATERIAL TAKEN FROM THE GROUP CONSISTING OF POLYPROPYLENE AND POLYALLOMER, THE JUNCTIONS BETWEEN SAID FLANGES AND SPINE BEING OF THIN SECTION TO PERMIT SAID FLANGES TO BE FLEXED RELATIVE TO SAID SPINE, THE THICKNESS OF SAID THIN SECTIONS BEING ENTIRELY INSIDE SAID SPINE AND FLANGES WHEREBY SAID SPINE AND FLANGES PROVIDE A CHANNEL-SHAPED BINDING ELEMENT HAVING SUBSTANTIALLY SQUARE AND SLIGHTLY ROUNDED OUTER EDGES, THE OTHER OF SAID FLANGES HAVING OPENINGS THEREIN TO RECEIVE SAID HEADS SAID OPENING EACH COMPRISING A COMPLETELY CIRCULAR CONESHAPED ENTRANCE PORTION AND A COUNTERBORE PORTION BEYOND SAID CONE-SHAPED ENTRANCE PORTION WHICH FORMS A COMPLETELY CIRCULAR FLAT SHOULDER FACING OUTWARDLY, SAID HEADS BEING OF GREATER DIAMETER THAN THE OUTER END OF SAID CONESHAPED ENTRANCE PORTIONS, AND OF LESSER DIAMETER THAN THE INNER END OF SAID CONE-SHAPED PORTION, SAID HEADS BEING ALIGNED WITH SAID INNER ENDS WHEN THE FLANGES ARE BROUGHT TOGETHER TO PERMIT FORCING SAID HEADS THROUGH SIAD OUTER ENDS WHEN CONNECTING SAID OTHER FLANGES TO SAID BINDING POSTS, SAID HEADS HAVING COMPLETELY CIRCULAR INWARDLY FACING FLAT SHOULDERS COACTING WITH SAID COUNTERBORE SHOULDERS TO PERMANENTLY RETAIN SAID HEADS RELATIVE TO SAID OTHER FLANGE UPON RECEPTION OF SAID HEADS IN SAID COUNTERBORE PORTIONS.