| 摘要 |
<p>The present invention provides an unitary spine binder which comprises an elongated dorsal hinge bearing pairs of opposing and complementary male and female ring elements having known male fastener and female fastener, respectively. Each pair of ring elements also comprise a concave distal end on one element, and a complementary convex distal end on the other element. When the distal ends of the ring elements are moved towards each other, the male and female fasteners reversibly engage with each other so that each pair of ring elements, in cooperation with the dorsal hinge, forms substantially a ring to secure sheet paper by occupying a pre-punched hole in the paper. At the same time, the concave and convex distal ends also engage, so that the sidewalls of the concave distal end engages the convex distal end to protect the fasteners against disengagement by torsional and lateral forces.</p> |
