| 摘要 |
<p>A trap-door assembly suitable for use in a pavement and giving access to an hotel cellar comprises a metal frame 10, 12, a door 2 pivoted on pins 22 attached to an angle bracket 20 and an inverted V-section stop 30; the pins are retained in L-shaped slots 24 in the frame members 10. During opening the door it first pivots on the pins until the edge 18 of the bracket contacts the stop 30 when the pins slide first horizontally then vertically down, the door is then held in the vertical position by the stop 30 and the top edge of member 12 (Figure 4). To close the door it is lifted and tilted until the other end of bracket 20 contacts stop 30 when the pins are forced back into the closed position. <IMAGE></p> |
