| 摘要 |
<p>The hinging loading ramp pivots at one end on a fixed on, and has at the other a bridge plate to the surface of the lorry platform etc. When not in use the plate extends downwards, swinging up into the plane of the ramp for use. A toggle linkage (2) hinges at one end at a point below the hinging ramp (1), and is attached at the other below the bridge plate (3). The junction point between the two arms of the linkage is attached (4) to a rope (5), reeved round a pulley (6) mounted below the hinging ramp to a fixed point (7) below. With the bridge plate swung down, the junction point (4) is below the line (8) joining the points at which the linkage is attached (9, 10) to hinging ramp and bridge plate. When the ramp is swung right up, this point is above this line, and descends below it, again on swinging down to bring the bridge plate onto the lorry plateform (21).</p> |
