Published on December 26, 2017
It is an application of scissors mechanism.
The bridge (for pedestrians) is stretched and contracted by two brown motors turning red bars.
Black weights are for balancing the bridge weight partly.
When stretched, bridge surface is formed by blue, violet and green plates (shown on lower left side). Their rotary axes are not in horizontal plane when stretched to avoid dead positions. It causes slits on the bridge surface and oscillation of the floor plates.
See a related design very elegant:
where it seems that the author does not pay attention to dead positions of the floor plates.
STEP files of this video:
Inventor files:
