| 摘要 |
<p>The door is particularly for an animal stall, having a Z-section stationary metal frame, and a swing frame of metal angle-section enclosing a core with double walls. The swing frame comprises metal members at right angles to each other and screwed or riveted together. Their cross-section (3) is such that the outside surface of each wall (9, 10) of the core (11) bears against the inside surface (4, 8) of its respective outer portion. The edge of one wall (9) is enclosed by the frame member with its end face clear of it, and the intervening space between the walls, and also that between the walls and the metal members, is completely filled with foam material.</p> |
