| 摘要 |
<p>The fastener may secure the components of an unframed picture i.e. the backing board and the glass cover. It comprises sheathed helical springs with hooked ends and a common anchorage. Each spring has a hook and a ring on opposite ends, the hook comprising an assymetric 'U' section plate, and the rings threading onto an anchor ring. A bar with eyelets on each end threads onto two of the springs, being slid normal to the springs and in relation to the ring to tension the fastener as required for a mounting.</p> |
